Built-in template tags and filters

This document describes Django's built-in template tags and filters. It isrecommended that you use the automatic documentation, if available, as this will also includedocumentation for any custom tags or filters installed.

Built-in tag reference

autoescape

Controls the current auto-escaping behavior. This tag takes either on oroff as an argument and that determines whether auto-escaping is in effectinside the block. The block is closed with an endautoescape ending tag.

When auto-escaping is in effect, all variable content has HTML escaping appliedto it before placing the result into the output (but after any filters havebeen applied). This is equivalent to manually applying the escapefilter to each variable.

The only exceptions are variables that are already marked as "safe" fromescaping, either by the code that populated the variable, or because it has hadthe safe or escape filters applied.

Sample usage:

  1. {% autoescape on %}
  2. {{ body }}
  3. {% endautoescape %}

block

Defines a block that can be overridden by child templates. SeeTemplate inheritance for more information.

comment

Ignores everything between {% comment %} and {% endcomment %}.An optional note may be inserted in the first tag. For example, this isuseful when commenting out code for documenting why the code was disabled.

Sample usage:

  1. <p>Rendered text with {{ pub_date|date:"c" }}</p>
  2. {% comment "Optional note" %}
  3. <p>Commented out text with {{ create_date|date:"c" }}</p>
  4. {% endcomment %}

comment tags cannot be nested.

csrf_token

This tag is used for CSRF protection, as described in the documentation forCross Site Request Forgeries.

cycle

Produces one of its arguments each time this tag is encountered. The firstargument is produced on the first encounter, the second argument on the secondencounter, and so forth. Once all arguments are exhausted, the tag cycles tothe first argument and produces it again.

This tag is particularly useful in a loop:

  1. {% for o in some_list %}
  2. <tr class="{% cycle 'row1' 'row2' %}">
  3. ...
  4. </tr>
  5. {% endfor %}

The first iteration produces HTML that refers to class row1, the second torow2, the third to row1 again, and so on for each iteration of theloop.

You can use variables, too. For example, if you have two template variables,rowvalue1 and rowvalue2, you can alternate between their values likethis:

  1. {% for o in some_list %}
  2. <tr class="{% cycle rowvalue1 rowvalue2 %}">
  3. ...
  4. </tr>
  5. {% endfor %}

Variables included in the cycle will be escaped. You can disable auto-escapingwith:

  1. {% for o in some_list %}
  2. <tr class="{% autoescape off %}{% cycle rowvalue1 rowvalue2 %}{% endautoescape %}">
  3. ...
  4. </tr>
  5. {% endfor %}

You can mix variables and strings:

  1. {% for o in some_list %}
  2. <tr class="{% cycle 'row1' rowvalue2 'row3' %}">
  3. ...
  4. </tr>
  5. {% endfor %}

In some cases you might want to refer to the current value of a cyclewithout advancing to the next value. To do this,just give the {% cycle %} tag a name, using "as", like this:

  1. {% cycle 'row1' 'row2' as rowcolors %}

From then on, you can insert the current value of the cycle wherever you'd likein your template by referencing the cycle name as a context variable. If youwant to move the cycle to the next value independently of the originalcycle tag, you can use another cycle tag and specify the name of thevariable. So, the following template:

  1. <tr>
  2. <td class="{% cycle 'row1' 'row2' as rowcolors %}">...</td>
  3. <td class="{{ rowcolors }}">...</td>
  4. </tr>
  5. <tr>
  6. <td class="{% cycle rowcolors %}">...</td>
  7. <td class="{{ rowcolors }}">...</td>
  8. </tr>

would output:

  1. <tr>
  2. <td class="row1">...</td>
  3. <td class="row1">...</td>
  4. </tr>
  5. <tr>
  6. <td class="row2">...</td>
  7. <td class="row2">...</td>
  8. </tr>

You can use any number of values in a cycle tag, separated by spaces.Values enclosed in single quotes (') or double quotes (") are treatedas string literals, while values without quotes are treated as templatevariables.

By default, when you use the as keyword with the cycle tag, theusage of {% cycle %} that initiates the cycle will itself producethe first value in the cycle. This could be a problem if you want touse the value in a nested loop or an included template. If you only wantto declare the cycle but not produce the first value, you can add asilent keyword as the last keyword in the tag. For example:

  1. {% for obj in some_list %}
  2. {% cycle 'row1' 'row2' as rowcolors silent %}
  3. <tr class="{{ rowcolors }}">{% include "subtemplate.html" %}</tr>
  4. {% endfor %}

This will output a list of <tr> elements with classalternating between row1 and row2. The subtemplate will haveaccess to rowcolors in its context and the value will match the classof the <tr> that encloses it. If the silent keyword were to beomitted, row1 and row2 would be emitted as normal text, outside the<tr> element.

When the silent keyword is used on a cycle definition, the silenceautomatically applies to all subsequent uses of that specific cycle tag.The following template would output nothing, even though the secondcall to {% cycle %} doesn't specify silent:

  1. {% cycle 'row1' 'row2' as rowcolors silent %}
  2. {% cycle rowcolors %}

You can use the resetcycle tag to make a {% cycle %} tag restartfrom its first value when it's next encountered.

debug

Outputs a whole load of debugging information, including the current contextand imported modules.

extends

Signals that this template extends a parent template.

This tag can be used in two ways:

  • {% extends "base.html" %} (with quotes) uses the literal value"base.html" as the name of the parent template to extend.
  • {% extends variable %} uses the value of variable. If the variableevaluates to a string, Django will use that string as the name of theparent template. If the variable evaluates to a Template object,Django will use that object as the parent template.
    See Template inheritance for more information.

Normally the template name is relative to the template loader's root directory.A string argument may also be a relative path starting with ./ or ../.For example, assume the following directory structure:

  1. dir1/
  2. template.html
  3. base2.html
  4. my/
  5. base3.html
  6. base1.html

In template.html, the following paths would be valid:

  1. {% extends "./base2.html" %}
  2. {% extends "../base1.html" %}
  3. {% extends "./my/base3.html" %}

filter

Filters the contents of the block through one or more filters. Multiplefilters can be specified with pipes and filters can have arguments, just asin variable syntax.

Note that the block includes all the text between the filter andendfilter tags.

Sample usage:

  1. {% filter force_escape|lower %}
  2. This text will be HTML-escaped, and will appear in all lowercase.
  3. {% endfilter %}

注解

The escape and safe filters are not acceptablearguments. Instead, use the autoescape tag to manage autoescapingfor blocks of template code.

firstof

Outputs the first argument variable that is not False. Outputs nothing ifall the passed variables are False.

Sample usage:

  1. {% firstof var1 var2 var3 %}

This is equivalent to:

  1. {% if var1 %}
  2. {{ var1 }}
  3. {% elif var2 %}
  4. {{ var2 }}
  5. {% elif var3 %}
  6. {{ var3 }}
  7. {% endif %}

You can also use a literal string as a fallback value in case allpassed variables are False:

  1. {% firstof var1 var2 var3 "fallback value" %}

This tag auto-escapes variable values. You can disable auto-escaping with:

  1. {% autoescape off %}
  2. {% firstof var1 var2 var3 "<strong>fallback value</strong>" %}
  3. {% endautoescape %}

Or if only some variables should be escaped, you can use:

  1. {% firstof var1 var2|safe var3 "<strong>fallback value</strong>"|safe %}

You can use the syntax {% firstof var1 var2 var3 as value %} to store theoutput inside a variable.

for

Loops over each item in an array, making the item available in a contextvariable. For example, to display a list of athletes provided inathlete_list:

  1. <ul>
  2. {% for athlete in athlete_list %}
  3. <li>{{ athlete.name }}</li>
  4. {% endfor %}
  5. </ul>

You can loop over a list in reverse by using{% for obj in list reversed %}.

If you need to loop over a list of lists, you can unpack the valuesin each sublist into individual variables. For example, if your contextcontains a list of (x,y) coordinates called points, you could use thefollowing to output the list of points:

  1. {% for x, y in points %}
  2. There is a point at {{ x }},{{ y }}
  3. {% endfor %}

This can also be useful if you need to access the items in a dictionary.For example, if your context contained a dictionary data, the followingwould display the keys and values of the dictionary:

  1. {% for key, value in data.items %}
  2. {{ key }}: {{ value }}
  3. {% endfor %}

Keep in mind that for the dot operator, dictionary key lookup takes precedenceover method lookup. Therefore if the data dictionary contains a key named'items', data.items will return data['items'] instead ofdata.items(). Avoid adding keys that are named like dictionary methods ifyou want to use those methods in a template (items, values, keys,etc.). Read more about the lookup order of the dot operator in thedocumentation of template variables.

The for loop sets a number of variables available within the loop:

VariableDescription
forloop.counterThe current iteration of the loop (1-indexed)
forloop.counter0The current iteration of the loop (0-indexed)
forloop.revcounterThe number of iterations from the end of theloop (1-indexed)
forloop.revcounter0The number of iterations from the end of theloop (0-indexed)
forloop.firstTrue if this is the first time through the loop
forloop.lastTrue if this is the last time through the loop
forloop.parentloopFor nested loops, this is the loop surroundingthe current one

for … empty

The for tag can take an optional {% empty %} clause whose text isdisplayed if the given array is empty or could not be found:

  1. <ul>
  2. {% for athlete in athlete_list %}
  3. <li>{{ athlete.name }}</li>
  4. {% empty %}
  5. <li>Sorry, no athletes in this list.</li>
  6. {% endfor %}
  7. </ul>

The above is equivalent to — but shorter, cleaner, and possibly fasterthan — the following:

  1. <ul>
  2. {% if athlete_list %}
  3. {% for athlete in athlete_list %}
  4. <li>{{ athlete.name }}</li>
  5. {% endfor %}
  6. {% else %}
  7. <li>Sorry, no athletes in this list.</li>
  8. {% endif %}
  9. </ul>

if

The {% if %} tag evaluates a variable, and if that variable is "true" (i.e.exists, is not empty, and is not a false boolean value) the contents of theblock are output:

  1. {% if athlete_list %}
  2. Number of athletes: {{ athlete_list|length }}
  3. {% elif athlete_in_locker_room_list %}
  4. Athletes should be out of the locker room soon!
  5. {% else %}
  6. No athletes.
  7. {% endif %}

In the above, if athlete_list is not empty, the number of athletes will bedisplayed by the {{ athlete_list|length }} variable.

As you can see, the if tag may take one or several {% elif %}clauses, as well as an {% else %} clause that will be displayed if allprevious conditions fail. These clauses are optional.

Boolean operators

if tags may use and, or or not to test a number ofvariables or to negate a given variable:

  1. {% if athlete_list and coach_list %}
  2. Both athletes and coaches are available.
  3. {% endif %}
  4.  
  5. {% if not athlete_list %}
  6. There are no athletes.
  7. {% endif %}
  8.  
  9. {% if athlete_list or coach_list %}
  10. There are some athletes or some coaches.
  11. {% endif %}
  12.  
  13. {% if not athlete_list or coach_list %}
  14. There are no athletes or there are some coaches.
  15. {% endif %}
  16.  
  17. {% if athlete_list and not coach_list %}
  18. There are some athletes and absolutely no coaches.
  19. {% endif %}

Use of both and and or clauses within the same tag is allowed, withand having higher precedence than or e.g.:

  1. {% if athlete_list and coach_list or cheerleader_list %}

will be interpreted like:

  1. if (athlete_list and coach_list) or cheerleader_list

Use of actual parentheses in the if tag is invalid syntax. If you needthem to indicate precedence, you should use nested if tags.

if tags may also use the operators ==, !=, <, >,<=, >=, in, not in, is, and is not which work asfollows:

== operator

Equality. Example:

  1. {% if somevar == "x" %}
  2. This appears if variable somevar equals the string "x"
  3. {% endif %}
!= operator

Inequality. Example:

  1. {% if somevar != "x" %}
  2. This appears if variable somevar does not equal the string "x",
  3. or if somevar is not found in the context
  4. {% endif %}
< operator

Less than. Example:

  1. {% if somevar < 100 %}
  2. This appears if variable somevar is less than 100.
  3. {% endif %}
> operator

Greater than. Example:

  1. {% if somevar > 0 %}
  2. This appears if variable somevar is greater than 0.
  3. {% endif %}
<= operator

Less than or equal to. Example:

  1. {% if somevar <= 100 %}
  2. This appears if variable somevar is less than 100 or equal to 100.
  3. {% endif %}
>= operator

Greater than or equal to. Example:

  1. {% if somevar >= 1 %}
  2. This appears if variable somevar is greater than 1 or equal to 1.
  3. {% endif %}
in operator

Contained within. This operator is supported by many Python containers to testwhether the given value is in the container. The following are some examplesof how x in y will be interpreted:

  1. {% if "bc" in "abcdef" %}
  2. This appears since "bc" is a substring of "abcdef"
  3. {% endif %}
  4.  
  5. {% if "hello" in greetings %}
  6. If greetings is a list or set, one element of which is the string
  7. "hello", this will appear.
  8. {% endif %}
  9.  
  10. {% if user in users %}
  11. If users is a QuerySet, this will appear if user is an
  12. instance that belongs to the QuerySet.
  13. {% endif %}
not in operator

Not contained within. This is the negation of the in operator.

is operator

Object identity. Tests if two values are the same object. Example:

  1. {% if somevar is True %}
  2. This appears if and only if somevar is True.
  3. {% endif %}
  4.  
  5. {% if somevar is None %}
  6. This appears if somevar is None, or if somevar is not found in the context.
  7. {% endif %}
is not operator

Negated object identity. Tests if two values are not the same object. This isthe negation of the is operator. Example:

  1. {% if somevar is not True %}
  2. This appears if somevar is not True, or if somevar is not found in the
  3. context.
  4. {% endif %}
  5.  
  6. {% if somevar is not None %}
  7. This appears if and only if somevar is not None.
  8. {% endif %}

Filters

You can also use filters in the if expression. For example:

  1. {% if messages|length >= 100 %}
  2. You have lots of messages today!
  3. {% endif %}

Complex expressions

All of the above can be combined to form complex expressions. For suchexpressions, it can be important to know how the operators are grouped when theexpression is evaluated - that is, the precedence rules. The precedence of theoperators, from lowest to highest, is as follows:

  • or
  • and
  • not
  • in
  • ==, !=, <, >, <=, >=
    (This follows Python exactly). So, for example, the following complexif tag:
  1. {% if a == b or c == d and e %}

…will be interpreted as:

  1. (a == b) or ((c == d) and e)

If you need different precedence, you will need to use nested if tags.Sometimes that is better for clarity anyway, for the sake of those who do notknow the precedence rules.

The comparison operators cannot be 'chained' like in Python or in mathematicalnotation. For example, instead of using:

  1. {% if a > b > c %} (WRONG)

you should use:

  1. {% if a > b and b > c %}

ifequal and ifnotequal

{% ifequal a b %} … {% endifequal %} is an obsolete way to write{% if a == b %} … {% endif %}. Likewise, {% ifnotequal a b %} …
{% endifnotequal %}
is superseded by {% if a != b %} … {% endif %}.The ifequal and ifnotequal tags will be deprecated in a future release.

ifchanged

Check if a value has changed from the last iteration of a loop.

The {% ifchanged %} block tag is used within a loop. It has two possibleuses.

  • Checks its own rendered contents against its previous state and onlydisplays the content if it has changed. For example, this displays a list ofdays, only displaying the month if it changes:
  1. <h1>Archive for {{ year }}</h1>
  2.  
  3. {% for date in days %}
  4. {% ifchanged %}<h3>{{ date|date:"F" }}</h3>{% endifchanged %}
  5. <a href="{{ date|date:"M/d"|lower }}/">{{ date|date:"j" }}</a>
  6. {% endfor %}
  • If given one or more variables, check whether any variable has changed.For example, the following shows the date every time it changes, whileshowing the hour if either the hour or the date has changed:
  1. {% for date in days %}
  2. {% ifchanged date.date %} {{ date.date }} {% endifchanged %}
  3. {% ifchanged date.hour date.date %}
  4. {{ date.hour }}
  5. {% endifchanged %}
  6. {% endfor %}

The ifchanged tag can also take an optional {% else %} clause thatwill be displayed if the value has not changed:

  1. {% for match in matches %}
  2. <div style="background-color:
  3. {% ifchanged match.ballot_id %}
  4. {% cycle "red" "blue" %}
  5. {% else %}
  6. gray
  7. {% endifchanged %}
  8. ">{{ match }}</div>
  9. {% endfor %}

include

Loads a template and renders it with the current context. This is a way of"including" other templates within a template.

The template name can either be a variable or a hard-coded (quoted) string,in either single or double quotes.

This example includes the contents of the template "foo/bar.html":

  1. {% include "foo/bar.html" %}

Normally the template name is relative to the template loader's root directory.A string argument may also be a relative path starting with ./ or ../as described in the extends tag.

This example includes the contents of the template whose name is contained inthe variable template_name:

  1. {% include template_name %}

The variable may also be any object with a render() method that accepts acontext. This allows you to reference a compiled Template in your context.

An included template is rendered within the context of the template thatincludes it. This example produces the output "Hello, John!":

  • Context: variable person is set to "John" and variable greetingis set to "Hello".

  • Template:

  1. {% include "name_snippet.html" %}
  • The name_snippet.html template:
  1. {{ greeting }}, {{ person|default:"friend" }}!

You can pass additional context to the template using keyword arguments:

  1. {% include "name_snippet.html" with person="Jane" greeting="Hello" %}

If you want to render the context only with the variables provided (or evenno variables at all), use the only option. No other variables areavailable to the included template:

  1. {% include "name_snippet.html" with greeting="Hi" only %}

注解

The include tag should be considered as an implementation of"render this subtemplate and include the HTML", not as "parse thissubtemplate and include its contents as if it were part of the parent".This means that there is no shared state between included templates —each include is a completely independent rendering process.

Blocks are evaluated before they are included. This means that a templatethat includes blocks from another will contain blocks that have alreadybeen evaluated and rendered - not blocks that can be overridden by, forexample, an extending template.

load

Loads a custom template tag set.

For example, the following template would load all the tags and filtersregistered in somelibrary and otherlibrary located in packagepackage:

  1. {% load somelibrary package.otherlibrary %}

You can also selectively load individual filters or tags from a library, usingthe from argument. In this example, the template tags/filters named fooand bar will be loaded from somelibrary:

  1. {% load foo bar from somelibrary %}

See Custom tag and filter libraries formore information.

lorem

Displays random "lorem ipsum" Latin text. This is useful for providing sampledata in templates.

Usage:

  1. {% lorem [count] [method] [random] %}

The {% lorem %} tag can be used with zero, one, two or three arguments.The arguments are:

ArgumentDescription
countA number (or variable) containing the number of paragraphs orwords to generate (default is 1).
methodEither w for words, p for HTML paragraphs or bfor plain-text paragraph blocks (default is b).
randomThe word random, which if given, does not use the commonparagraph ("Lorem ipsum dolor sit amet…") when generatingtext.

Examples:

  • {% lorem %} will output the common "lorem ipsum" paragraph.
  • {% lorem 3 p %} will output the common "lorem ipsum" paragraphand two random paragraphs each wrapped in HTML <p> tags.
  • {% lorem 2 w random %} will output two random Latin words.

now

Displays the current date and/or time, using a format according to the givenstring. Such string can contain format specifiers characters as describedin the date filter section.

Example:

  1. It is {% now "jS F Y H:i" %}

Note that you can backslash-escape a format string if you want to use the"raw" value. In this example, both "o" and "f" are backslash-escaped, becauseotherwise each is a format string that displays the year and the time,respectively:

  1. It is the {% now "jS \o\f F" %}

This would display as "It is the 4th of September".

注解

The format passed can also be one of the predefined onesDATE_FORMAT, DATETIME_FORMAT,SHORT_DATE_FORMAT or SHORT_DATETIME_FORMAT.The predefined formats may vary depending on the current locale andif Format localization is enabled, e.g.:

  1. It is {% now "SHORT_DATETIME_FORMAT" %}

You can also use the syntax {% now "Y" as current_year %} to store theoutput (as a string) inside a variable. This is useful if you want to use{% now %} inside a template tag like blocktrans for example:

  1. {% now "Y" as current_year %}
  2. {% blocktrans %}Copyright {{ current_year }}{% endblocktrans %}

regroup

Regroups a list of alike objects by a common attribute.

This complex tag is best illustrated by way of an example: say that citiesis a list of cities represented by dictionaries containing "name","population", and "country" keys:

  1. cities = [
  2. {'name': 'Mumbai', 'population': '19,000,000', 'country': 'India'},
  3. {'name': 'Calcutta', 'population': '15,000,000', 'country': 'India'},
  4. {'name': 'New York', 'population': '20,000,000', 'country': 'USA'},
  5. {'name': 'Chicago', 'population': '7,000,000', 'country': 'USA'},
  6. {'name': 'Tokyo', 'population': '33,000,000', 'country': 'Japan'},
  7. ]

…and you'd like to display a hierarchical list that is ordered by country,like this:

  • India
    • Mumbai: 19,000,000
    • Calcutta: 15,000,000
  • USA
    • New York: 20,000,000
    • Chicago: 7,000,000
  • Japan
    • Tokyo: 33,000,000
      You can use the {% regroup %} tag to group the list of cities by country.The following snippet of template code would accomplish this:
  1. {% regroup cities by country as country_list %}
  2.  
  3. <ul>
  4. {% for country in country_list %}
  5. <li>{{ country.grouper }}
  6. <ul>
  7. {% for city in country.list %}
  8. <li>{{ city.name }}: {{ city.population }}</li>
  9. {% endfor %}
  10. </ul>
  11. </li>
  12. {% endfor %}
  13. </ul>

Let's walk through this example. {% regroup %} takes three arguments: thelist you want to regroup, the attribute to group by, and the name of theresulting list. Here, we're regrouping the cities list by the countryattribute and calling the result country_list.

{% regroup %} produces a list (in this case, country_list) ofgroup objects. Group objects are instances ofnamedtuple() with two fields:

  • grouper — the item that was grouped by (e.g., the string "India" or"Japan").
  • list — a list of all items in this group (e.g., a list of all citieswith country='India').
    Because {% regroup %} produces namedtuple() objects,you can also write the previous example as:
  1. {% regroup cities by country as country_list %}
  2.  
  3. <ul>
  4. {% for country, local_cities in country_list %}
  5. <li>{{ country }}
  6. <ul>
  7. {% for city in local_cities %}
  8. <li>{{ city.name }}: {{ city.population }}</li>
  9. {% endfor %}
  10. </ul>
  11. </li>
  12. {% endfor %}
  13. </ul>

Note that {% regroup %} does not order its input! Our example relies onthe fact that the cities list was ordered by country in the first place.If the cities list did not order its members by country, theregrouping would naively display more than one group for a single country. Forexample, say the cities list was set to this (note that the countries are notgrouped together):

  1. cities = [
  2. {'name': 'Mumbai', 'population': '19,000,000', 'country': 'India'},
  3. {'name': 'New York', 'population': '20,000,000', 'country': 'USA'},
  4. {'name': 'Calcutta', 'population': '15,000,000', 'country': 'India'},
  5. {'name': 'Chicago', 'population': '7,000,000', 'country': 'USA'},
  6. {'name': 'Tokyo', 'population': '33,000,000', 'country': 'Japan'},
  7. ]

With this input for cities, the example {% regroup %} template codeabove would result in the following output:

  • India
    • Mumbai: 19,000,000
  • USA
    • New York: 20,000,000
  • India
    • Calcutta: 15,000,000
  • USA
    • Chicago: 7,000,000
  • Japan
    • Tokyo: 33,000,000
      The easiest solution to this gotcha is to make sure in your view code that thedata is ordered according to how you want to display it.

Another solution is to sort the data in the template using thedictsort filter, if your data is in a list of dictionaries:

  1. {% regroup cities|dictsort:"country" by country as country_list %}

Grouping on other properties

Any valid template lookup is a legal grouping attribute for the regrouptag, including methods, attributes, dictionary keys and list items. Forexample, if the "country" field is a foreign key to a class withan attribute "description," you could use:

  1. {% regroup cities by country.description as country_list %}

Or, if country is a field with choices, it will have aget_FOO_display() method available as anattribute, allowing you to group on the display string rather than thechoices key:

  1. {% regroup cities by get_country_display as country_list %}

{{ country.grouper }} will now display the value fields from thechoices set rather than the keys.

resetcycle

Resets a previous cycle so that it restarts from its first item at its nextencounter. Without arguments, {% resetcycle %} will reset the last{% cycle %} defined in the template.

Example usage:

  1. {% for coach in coach_list %}
  2. <h1>{{ coach.name }}</h1>
  3. {% for athlete in coach.athlete_set.all %}
  4. <p class="{% cycle 'odd' 'even' %}">{{ athlete.name }}</p>
  5. {% endfor %}
  6. {% resetcycle %}
  7. {% endfor %}

This example would return this HTML:

  1. <h1>José Mourinho</h1>
  2. <p class="odd">Thibaut Courtois</p>
  3. <p class="even">John Terry</p>
  4. <p class="odd">Eden Hazard</p>
  5.  
  6. <h1>Carlo Ancelotti</h1>
  7. <p class="odd">Manuel Neuer</p>
  8. <p class="even">Thomas Müller</p>

Notice how the first block ends with class="odd" and the new one startswith class="odd". Without the {% resetcycle %} tag, the second blockwould start with class="even".

You can also reset named cycle tags:

  1. {% for item in list %}
  2. <p class="{% cycle 'odd' 'even' as stripe %} {% cycle 'major' 'minor' 'minor' 'minor' 'minor' as tick %}">
  3. {{ item.data }}
  4. </p>
  5. {% ifchanged item.category %}
  6. <h1>{{ item.category }}</h1>
  7. {% if not forloop.first %}{% resetcycle tick %}{% endif %}
  8. {% endifchanged %}
  9. {% endfor %}

In this example, we have both the alternating odd/even rows and a "major" rowevery fifth row. Only the five-row cycle is reset when a category changes.

spaceless

Removes whitespace between HTML tags. This includes tabcharacters and newlines.

Example usage:

  1. {% spaceless %}
  2. <p>
  3. <a href="foo/">Foo</a>
  4. </p>
  5. {% endspaceless %}

This example would return this HTML:

  1. <p><a href="foo/">Foo</a></p>

Only space between tags is removed — not space between tags and text. Inthis example, the space around Hello won't be stripped:

  1. {% spaceless %}
  2. <strong>
  3. Hello
  4. </strong>
  5. {% endspaceless %}

templatetag

Outputs one of the syntax characters used to compose template tags.

Since the template system has no concept of "escaping", to display one of thebits used in template tags, you must use the {% templatetag %} tag.

The argument tells which template bit to output:

ArgumentOutputs
openblock{%
closeblock%}
openvariable{{
closevariable}}
openbrace{
closebrace}
opencomment{#
closecomment#}

Sample usage:

  1. {% templatetag openblock %} url 'entry_list' {% templatetag closeblock %}

url

Returns an absolute path reference (a URL without the domain name) matching agiven view and optional parameters. Any special characters in the resultingpath will be encoded using iri_to_uri().

This is a way to output links without violating the DRY principle by having tohard-code URLs in your templates:

  1. {% url 'some-url-name' v1 v2 %}

The first argument is a URL pattern name. It canbe a quoted literal or any other context variable. Additional arguments areoptional and should be space-separated values that will be used as arguments inthe URL. The example above shows passing positional arguments. Alternativelyyou may use keyword syntax:

  1. {% url 'some-url-name' arg1=v1 arg2=v2 %}

Do not mix both positional and keyword syntax in a single call. All argumentsrequired by the URLconf should be present.

For example, suppose you have a view, app_views.client, whose URLconftakes a client ID (here, client() is a method inside the views fileapp_views.py). The URLconf line might look like this:

  1. path('client/<int:id>/', app_views.client, name='app-views-client')

If this app's URLconf is included into the project's URLconf under a pathsuch as this:

  1. path('clients/', include('project_name.app_name.urls'))

…then, in a template, you can create a link to this view like this:

  1. {% url 'app-views-client' client.id %}

The template tag will output the string /clients/client/123/.

Note that if the URL you're reversing doesn't exist, you'll get anNoReverseMatch exception raised, which will cause yoursite to display an error page.

If you'd like to retrieve a URL without displaying it, you can use a slightlydifferent call:

  1. {% url 'some-url-name' arg arg2 as the_url %}
  2.  
  3. <a href="{{ the_url }}">I'm linking to {{ the_url }}</a>

The scope of the variable created by the as var syntax is the{% block %} in which the {% url %} tag appears.

This {% url … as var %} syntax will not cause an error if the view ismissing. In practice you'll use this to link to views that are optional:

  1. {% url 'some-url-name' as the_url %}
  2. {% if the_url %}
  3. <a href="{{ the_url }}">Link to optional stuff</a>
  4. {% endif %}

If you'd like to retrieve a namespaced URL, specify the fully qualified name:

  1. {% url 'myapp:view-name' %}

This will follow the normal namespaced URL resolution strategy, including using any hints providedby the context as to the current application.

警告

Don't forget to put quotes around the URL pattern name, otherwise thevalue will be interpreted as a context variable!

verbatim

Stops the template engine from rendering the contents of this block tag.

A common use is to allow a JavaScript template layer that collides withDjango's syntax. For example:

  1. {% verbatim %}
  2. {{if dying}}Still alive.{{/if}}
  3. {% endverbatim %}

You can also designate a specific closing tag, allowing the use of{% endverbatim %} as part of the unrendered contents:

  1. {% verbatim myblock %}
  2. Avoid template rendering via the {% verbatim %}{% endverbatim %} block.
  3. {% endverbatim myblock %}

widthratio

For creating bar charts and such, this tag calculates the ratio of a givenvalue to a maximum value, and then applies that ratio to a constant.

For example:

  1. <img src="bar.png" alt="Bar"
  2. height="10" width="{% widthratio this_value max_value max_width %}">

If this_value is 175, max_value is 200, and max_width is 100, theimage in the above example will be 88 pixels wide(because 175/200 = .875; .875 * 100 = 87.5 which is rounded up to 88).

In some cases you might want to capture the result of widthratio in avariable. It can be useful, for instance, in a blocktrans like this:

  1. {% widthratio this_value max_value max_width as width %}
  2. {% blocktrans %}The width is: {{ width }}{% endblocktrans %}

with

Caches a complex variable under a simpler name. This is useful when accessingan "expensive" method (e.g., one that hits the database) multiple times.

For example:

  1. {% with total=business.employees.count %}
  2. {{ total }} employee{{ total|pluralize }}
  3. {% endwith %}

The populated variable (in the example above, total) is only availablebetween the {% with %} and {% endwith %} tags.

You can assign more than one context variable:

  1. {% with alpha=1 beta=2 %}
  2. ...
  3. {% endwith %}

注解

The previous more verbose format is still supported:{% with business.employees.count as total %}

Built-in filter reference

add

Adds the argument to the value.

For example:

  1. {{ value|add:"2" }}

If value is 4, then the output will be 6.

This filter will first try to coerce both values to integers. If this fails,it'll attempt to add the values together anyway. This will work on some datatypes (strings, list, etc.) and fail on others. If it fails, the result willbe an empty string.

For example, if we have:

  1. {{ first|add:second }}

and first is [1, 2, 3] and second is [4, 5, 6], then theoutput will be [1, 2, 3, 4, 5, 6].

警告

Strings that can be coerced to integers will be summed, notconcatenated, as in the first example above.

addslashes

Adds slashes before quotes. Useful for escaping strings in CSV, for example.

For example:

  1. {{ value|addslashes }}

If value is "I'm using Django", the output will be"I\'m using Django".

capfirst

Capitalizes the first character of the value. If the first character is nota letter, this filter has no effect.

For example:

  1. {{ value|capfirst }}

If value is "django", the output will be "Django".

center

Centers the value in a field of a given width.

For example:

  1. "{{ value|center:"15" }}"

If value is "Django", the output will be " Django ".

cut

Removes all values of arg from the given string.

For example:

  1. {{ value|cut:" " }}

If value is "String with spaces", the output will be"Stringwithspaces".

date

Formats a date according to the given format.

Uses a similar format as PHP's date() function (https://php.net/date)with some differences.

注解

These format characters are not used in Django outside of templates. Theywere designed to be compatible with PHP to ease transitioning for designers.

Available format strings:

Format characterDescriptionExample output
Day
dDay of the month, 2 digits withleading zeros.'01' to '31'
jDay of the month without leadingzeros.'1' to '31'
DDay of the week, textual, 3 letters.'Fri'
lDay of the week, textual, long.'Friday'
SEnglish ordinal suffix for day of themonth, 2 characters.'st', 'nd', 'rd' or 'th'
wDay of the week, digits withoutleading zeros.'0' (Sunday) to '6' (Saturday)
zDay of the year.0 to 365
Week
WISO-8601 week number of year, withweeks starting on Monday.1, 53
Month
mMonth, 2 digits with leading zeros.'01' to '12'
nMonth without leading zeros.'1' to '12'
MMonth, textual, 3 letters.'Jan'
bMonth, textual, 3 letters, lowercase.'jan'
EMonth, locale specific alternativerepresentation usually used for longdate representation.'listopada' (for Polish locale, as opposed to 'Listopad')
FMonth, textual, long.'January'
NMonth abbreviation in Associated Pressstyle. Proprietary extension.'Jan.', 'Feb.', 'March', 'May'
tNumber of days in the given month.28 to 31
Year
yYear, 2 digits.'99'
YYear, 4 digits.'1999'
LBoolean for whether it's a leap year.True or False
oISO-8601 week-numbering year,corresponding to the ISO-8601 weeknumber (W) which uses leap weeks. See Yfor the more common year format.'1999'
Time
gHour, 12-hour format without leadingzeros.'1' to '12'
GHour, 24-hour format without leadingzeros.'0' to '23'
hHour, 12-hour format.'01' to '12'
HHour, 24-hour format.'00' to '23'
iMinutes.'00' to '59'
sSeconds, 2 digits with leading zeros.'00' to '59'
uMicroseconds.000000 to 999999
a'a.m.' or 'p.m.' (Note thatthis is slightly different than PHP'soutput, because this includes periodsto match Associated Press style.)'a.m.'
A'AM' or 'PM'.'AM'
fTime, in 12-hour hours and minutes,with minutes left off if they're zero.Proprietary extension.'1', '1:30'
PTime, in 12-hour hours, minutes and'a.m.'/'p.m.', with minutes left offif they're zero and the special-casestrings 'midnight' and 'noon' ifappropriate. Proprietary extension.'1 a.m.', '1:30 p.m.', 'midnight', 'noon', '12:30 p.m.'
Timezone
eTimezone name. Could be in any format,or might return an empty string,depending on the datetime.'', 'GMT', '-500', 'US/Eastern', etc.
IDaylight Savings Time, whether it'sin effect or not.'1' or '0'
ODifference to Greenwich time in hours.'+0200'
TTime zone of this machine.'EST', 'MDT'
ZTime zone offset in seconds. Theoffset for timezones west of UTC isalways negative, and for those east ofUTC is always positive.-43200 to 43200
Date/Time
cISO 8601 format. (Note: unlike othersformatters, such as "Z", "O" or "r",the "c" formatter will not add timezoneoffset if value is a naive datetime(see datetime.tzinfo).2008-01-02T10:30:00.000123+02:00,or 2008-01-02T10:30:00.000123 if the datetime is naive
rRFC 5322 formatted date.'Thu, 21 Dec 2000 16:01:07 +0200'
USeconds since the Unix Epoch(January 1 1970 00:00:00 UTC).

For example:

  1. {{ value|date:"D d M Y" }}

If value is a datetime object (e.g., the result ofdatetime.datetime.now()), the output will be the string'Wed 09 Jan 2008'.

The format passed can be one of the predefined ones DATE_FORMAT,DATETIME_FORMAT, SHORT_DATE_FORMAT orSHORT_DATETIME_FORMAT, or a custom format that uses the formatspecifiers shown in the table above. Note that predefined formats may varydepending on the current locale.

Assuming that USE_L10N is True and LANGUAGE_CODE is,for example, "es", then for:

  1. {{ value|date:"SHORT_DATE_FORMAT" }}

the output would be the string "09/01/2008" (the "SHORT_DATE_FORMAT"format specifier for the es locale as shipped with Django is "d/m/Y").

When used without a format string, the DATE_FORMAT format specifier isused. Assuming the same settings as the previous example:

  1. {{ value|date }}

outputs 9 de Enero de 2008 (the DATE_FORMAT format specifier for thees locale is r'j \d\e F \d\e Y'.

You can combine date with the time filter to render a fullrepresentation of a datetime value. E.g.:

  1. {{ value|date:"D d M Y" }} {{ value|time:"H:i" }}

default

If value evaluates to False, uses the given default. Otherwise, uses thevalue.

For example:

  1. {{ value|default:"nothing" }}

If value is "" (the empty string), the output will be nothing.

default_if_none

If (and only if) value is None, uses the given default. Otherwise, uses thevalue.

Note that if an empty string is given, the default value will not be used.Use the default filter if you want to fallback for empty strings.

For example:

  1. {{ value|default_if_none:"nothing" }}

If value is None, the output will be nothing.

dictsort

Takes a list of dictionaries and returns that list sorted by the key given inthe argument.

For example:

  1. {{ value|dictsort:"name" }}

If value is:

  1. [
  2. {'name': 'zed', 'age': 19},
  3. {'name': 'amy', 'age': 22},
  4. {'name': 'joe', 'age': 31},
  5. ]

then the output would be:

  1. [
  2. {'name': 'amy', 'age': 22},
  3. {'name': 'joe', 'age': 31},
  4. {'name': 'zed', 'age': 19},
  5. ]

You can also do more complicated things like:

  1. {% for book in books|dictsort:"author.age" %}
  2. * {{ book.title }} ({{ book.author.name }})
  3. {% endfor %}

If books is:

  1. [
  2. {'title': '1984', 'author': {'name': 'George', 'age': 45}},
  3. {'title': 'Timequake', 'author': {'name': 'Kurt', 'age': 75}},
  4. {'title': 'Alice', 'author': {'name': 'Lewis', 'age': 33}},
  5. ]

then the output would be:

  1. * Alice (Lewis)
  2. * 1984 (George)
  3. * Timequake (Kurt)

dictsort can also order a list of lists (or any other object implementinggetitem()) by elements at specified index. For example:

  1. {{ value|dictsort:0 }}

If value is:

  1. [
  2. ('a', '42'),
  3. ('c', 'string'),
  4. ('b', 'foo'),
  5. ]

then the output would be:

  1. [
  2. ('a', '42'),
  3. ('b', 'foo'),
  4. ('c', 'string'),
  5. ]

You must pass the index as an integer rather than a string. The followingproduce empty output:

  1. {{ values|dictsort:"0" }}

dictsortreversed

Takes a list of dictionaries and returns that list sorted in reverse order bythe key given in the argument. This works exactly the same as the above filter,but the returned value will be in reverse order.

divisibleby

Returns True if the value is divisible by the argument.

For example:

  1. {{ value|divisibleby:"3" }}

If value is 21, the output would be True.

escape

Escapes a string's HTML. Specifically, it makes these replacements:

  • < is converted to &lt;
  • > is converted to &gt;
  • ' (single quote) is converted to &#39;
  • " (double quote) is converted to &quot;
  • & is converted to &amp;
    Applying escape to a variable that would normally have auto-escapingapplied to the result will only result in one round of escaping being done. Soit is safe to use this function even in auto-escaping environments. If you wantmultiple escaping passes to be applied, use the force_escape filter.

For example, you can apply escape to fields when autoescape is off:

  1. {% autoescape off %}
  2. {{ title|escape }}
  3. {% endautoescape %}

escapejs

Escapes characters for use in JavaScript strings. This does not make thestring safe for use in HTML or JavaScript template literals, but does protectyou from syntax errors when using templates to generate JavaScript/JSON.

For example:

  1. {{ value|escapejs }}

If value is "testing\r\njavascript \'string" <b>escaping</b>",the output will be "testing\u000D\u000Ajavascript \u0027string\u0022 \u003Cb\u003Eescaping\u003C/b\u003E".

filesizeformat

Formats the value like a 'human-readable' file size (i.e. '13 KB','4.1 MB', '102 bytes', etc.).

For example:

  1. {{ value|filesizeformat }}

If value is 123456789, the output would be 117.7 MB.

File sizes and SI units

Strictly speaking, filesizeformat does not conform to the InternationalSystem of Units which recommends using KiB, MiB, GiB, etc. when byte sizesare calculated in powers of 1024 (which is the case here). Instead, Djangouses traditional unit names (KB, MB, GB, etc.) corresponding to names thatare more commonly used.

first

Returns the first item in a list.

For example:

  1. {{ value|first }}

If value is the list ['a', 'b', 'c'], the output will be 'a'.

floatformat

When used without an argument, rounds a floating-point number to one decimalplace — but only if there's a decimal part to be displayed. For example:

valueTemplateOutput
34.23234{{ value|floatformat }}34.2
34.00000{{ value|floatformat }}34
34.26000{{ value|floatformat }}34.3

If used with a numeric integer argument, floatformat rounds a number tothat many decimal places. For example:

valueTemplateOutput
34.23234{{ value|floatformat:3 }}34.232
34.00000{{ value|floatformat:3 }}34.000
34.26000{{ value|floatformat:3 }}34.260

Particularly useful is passing 0 (zero) as the argument which will round thefloat to the nearest integer.

valueTemplateOutput
34.23234{{ value|floatformat:"0" }}34
34.00000{{ value|floatformat:"0" }}34
39.56000{{ value|floatformat:"0" }}40

If the argument passed to floatformat is negative, it will round a numberto that many decimal places — but only if there's a decimal part to bedisplayed. For example:

valueTemplateOutput
34.23234{{ value|floatformat:"-3" }}34.232
34.00000{{ value|floatformat:"-3" }}34
34.26000{{ value|floatformat:"-3" }}34.260

Using floatformat with no argument is equivalent to using floatformatwith an argument of -1.

force_escape

Applies HTML escaping to a string (see the escape filter fordetails). This filter is applied immediately and returns a new, escapedstring. This is useful in the rare cases where you need multiple escaping orwant to apply other filters to the escaped results. Normally, you want to usethe escape filter.

For example, if you want to catch the <p> HTML elements created bythe linebreaks filter:

  1. {% autoescape off %}
  2. {{ body|linebreaks|force_escape }}
  3. {% endautoescape %}

get_digit

Given a whole number, returns the requested digit, where 1 is the right-mostdigit, 2 is the second-right-most digit, etc. Returns the original value forinvalid input (if input or argument is not an integer, or if argument is lessthan 1). Otherwise, output is always an integer.

For example:

  1. {{ value|get_digit:"2" }}

If value is 123456789, the output will be 8.

iriencode

Converts an IRI (Internationalized Resource Identifier) to a string that issuitable for including in a URL. This is necessary if you're trying to usestrings containing non-ASCII characters in a URL.

It's safe to use this filter on a string that has already gone through theurlencode filter.

For example:

  1. {{ value|iriencode }}

If value is "?test=1&me=2", the output will be "?test=1&amp;me=2".

join

Joins a list with a string, like Python's str.join(list)

For example:

  1. {{ value|join:" // " }}

If value is the list ['a', 'b', 'c'], the output will be the string"a // b // c".

json_script

New in Django 2.1:

Safely outputs a Python object as JSON, wrapped in a <script> tag, readyfor use with JavaScript.

Argument: HTML "id" of the <script> tag.

For example:

  1. {{ value|json_script:"hello-data" }}

If value is the dictionary {'hello': 'world'}, the output will be:

  1. <script id="hello-data" type="application/json">{"hello": "world"}</script>

The resulting data can be accessed in JavaScript like this:

  1. var value = JSON.parse(document.getElementById('hello-data').textContent);

XSS attacks are mitigated by escaping the characters "<", ">" and "&". Forexample if value is {'hello': 'world</script>&amp;'}, the output is:

  1. <script id="hello-data" type="application/json">{"hello": "world\\u003C/script\\u003E\\u0026amp;"}</script>

This is compatible with a strict Content Security Policy that prohibits in-pagescript execution. It also maintains a clean separation between passive data andexecutable code.

last

Returns the last item in a list.

For example:

  1. {{ value|last }}

If value is the list ['a', 'b', 'c', 'd'], the output will be thestring "d".

length

Returns the length of the value. This works for both strings and lists.

For example:

  1. {{ value|length }}

If value is ['a', 'b', 'c', 'd'] or "abcd", the output will be4.

The filter returns 0 for an undefined variable.

length_is

Returns True if the value's length is the argument, or False otherwise.

For example:

  1. {{ value|length_is:"4" }}

If value is ['a', 'b', 'c', 'd'] or "abcd", the output will beTrue.

linebreaks

Replaces line breaks in plain text with appropriate HTML; a singlenewline becomes an HTML line break (<br>) and a new linefollowed by a blank line becomes a paragraph break (</p>).

For example:

  1. {{ value|linebreaks }}

If value is Joel\nis a slug, the output will be <p>Joel<br>is a
slug</p>
.

linebreaksbr

Converts all newlines in a piece of plain text to HTML line breaks(<br>).

For example:

  1. {{ value|linebreaksbr }}

If value is Joel\nis a slug, the output will be Joel<br>is a
slug
.

linenumbers

Displays text with line numbers.

For example:

  1. {{ value|linenumbers }}

If value is:

  1. one
  2. two
  3. three

the output will be:

  1. 1. one
  2. 2. two
  3. 3. three

ljust

Left-aligns the value in a field of a given width.

Argument: field size

For example:

  1. "{{ value|ljust:"10" }}"

If value is Django, the output will be "Django ".

lower

Converts a string into all lowercase.

For example:

  1. {{ value|lower }}

If value is Totally LOVING this Album!, the output will betotally loving this album!.

make_list

Returns the value turned into a list. For a string, it's a list of characters.For an integer, the argument is cast to a string before creating a list.

For example:

  1. {{ value|make_list }}

If value is the string "Joel", the output would be the list['J', 'o', 'e', 'l']. If value is 123, the output will be thelist ['1', '2', '3'].

phone2numeric

Converts a phone number (possibly containing letters) to its numericalequivalent.

The input doesn't have to be a valid phone number. This will happily convertany string.

For example:

  1. {{ value|phone2numeric }}

If value is 800-COLLECT, the output will be 800-2655328.

pluralize

Returns a plural suffix if the value is not 1. By default, this suffix is's'.

Example:

  1. You have {{ num_messages }} message{{ num_messages|pluralize }}.

If num_messages is 1, the output will be You have 1 message.If num_messages is 2 the output will be You have 2 messages.

For words that require a suffix other than 's', you can provide an alternatesuffix as a parameter to the filter.

Example:

  1. You have {{ num_walruses }} walrus{{ num_walruses|pluralize:"es" }}.

For words that don't pluralize by simple suffix, you can specify both asingular and plural suffix, separated by a comma.

Example:

  1. You have {{ num_cherries }} cherr{{ num_cherries|pluralize:"y,ies" }}.

注解

Use blocktrans to pluralize translated strings.

pprint

A wrapper around pprint.pprint() — for debugging, really.

random

Returns a random item from the given list.

For example:

  1. {{ value|random }}

If value is the list ['a', 'b', 'c', 'd'], the output could be "b".

rjust

Right-aligns the value in a field of a given width.

Argument: field size

For example:

  1. "{{ value|rjust:"10" }}"

If value is Django, the output will be " Django".

safe

Marks a string as not requiring further HTML escaping prior to output. Whenautoescaping is off, this filter has no effect.

注解

If you are chaining filters, a filter applied after safe canmake the contents unsafe again. For example, the following codeprints the variable as is, unescaped:

  1. {{ var|safe|escape }}

safeseq

Applies the safe filter to each element of a sequence. Useful inconjunction with other filters that operate on sequences, such asjoin. For example:

  1. {{ some_list|safeseq|join:", " }}

You couldn't use the safe filter directly in this case, as it wouldfirst convert the variable into a string, rather than working with theindividual elements of the sequence.

slice

Returns a slice of the list.

Uses the same syntax as Python's list slicing. Seehttps://www.diveinto.org/python3/native-datatypes.html#slicinglistsfor an introduction.

Example:

  1. {{ some_list|slice:":2" }}

If some_list is ['a', 'b', 'c'], the output will be ['a', 'b'].

slugify

Converts to ASCII. Converts spaces to hyphens. Removes characters that aren'talphanumerics, underscores, or hyphens. Converts to lowercase. Also stripsleading and trailing whitespace.

For example:

  1. {{ value|slugify }}

If value is "Joel is a slug", the output will be "joel-is-a-slug".

stringformat

Formats the variable according to the argument, a string formatting specifier.This specifier uses the printf-style String Formatting syntax, with the exceptionthat the leading "%" is dropped.

For example:

  1. {{ value|stringformat:"E" }}

If value is 10, the output will be 1.000000E+01.

striptags

Makes all possible efforts to strip all [X]HTML tags.

For example:

  1. {{ value|striptags }}

If value is "<b>Joel</b> <button>is</button> a <span>slug</span>", theoutput will be "Joel is a slug".

No safety guarantee

Note that striptags doesn't give any guarantee about its output beingHTML safe, particularly with non valid HTML input. So NEVER apply thesafe filter to a striptags output. If you are looking for somethingmore robust, you can use the bleach Python library, notably itsclean method.

time

Formats a time according to the given format.

Given format can be the predefined one TIME_FORMAT, or a customformat, same as the date filter. Note that the predefined formatis locale-dependent.

For example:

  1. {{ value|time:"H:i" }}

If value is equivalent to datetime.datetime.now(), the output will bethe string "01:23".

Another example:

Assuming that USE_L10N is True and LANGUAGE_CODE is,for example, "de", then for:

  1. {{ value|time:"TIME_FORMAT" }}

the output will be the string "01:23" (The "TIME_FORMAT" formatspecifier for the de locale as shipped with Django is "H:i").

The time filter will only accept parameters in the format string thatrelate to the time of day, not the date (for obvious reasons). If you need toformat a date value, use the date filter instead (or alongtime if you need to render a full datetime value).

There is one exception the above rule: When passed a datetime value withattached timezone information (a time-zone-aware datetime instance) the time filter willaccept the timezone-related format specifiers 'e', 'O' , 'T' and 'Z'.

When used without a format string, the TIME_FORMAT format specifier isused:

  1. {{ value|time }}

is the same as:

  1. {{ value|time:"TIME_FORMAT" }}

timesince

Formats a date as the time since that date (e.g., "4 days, 6 hours").

Takes an optional argument that is a variable containing the date to use asthe comparison point (without the argument, the comparison point is now).For example, if blog_date is a date instance representing midnight on 1June 2006, and comment_date is a date instance for 08:00 on 1 June 2006,then the following would return "8 hours":

  1. {{ blog_date|timesince:comment_date }}

Comparing offset-naive and offset-aware datetimes will return an empty string.

Minutes is the smallest unit used, and "0 minutes" will be returned for anydate that is in the future relative to the comparison point.

timeuntil

Similar to timesince, except that it measures the time from now until thegiven date or datetime. For example, if today is 1 June 2006 andconference_date is a date instance holding 29 June 2006, then{{ conference_date|timeuntil }} will return "4 weeks".

Takes an optional argument that is a variable containing the date to use asthe comparison point (instead of now). If from_date contains 22 June2006, then the following will return "1 week":

  1. {{ conference_date|timeuntil:from_date }}

Comparing offset-naive and offset-aware datetimes will return an empty string.

Minutes is the smallest unit used, and "0 minutes" will be returned for anydate that is in the past relative to the comparison point.

title

Converts a string into titlecase by making words start with an uppercasecharacter and the remaining characters lowercase. This tag makes no effort tokeep "trivial words" in lowercase.

For example:

  1. {{ value|title }}

If value is "my FIRST post", the output will be "My First Post".

truncatechars

Truncates a string if it is longer than the specified number of characters.Truncated strings will end with a translatable ellipsis character ("…").

Argument: Number of characters to truncate to

For example:

  1. {{ value|truncatechars:7 }}

If value is "Joel is a slug", the output will be "Joel i…".

truncatechars_html

Similar to truncatechars, except that it is aware of HTML tags. Anytags that are opened in the string and not closed before the truncation pointare closed immediately after the truncation.

For example:

  1. {{ value|truncatechars_html:7 }}

If value is "<p>Joel is a slug</p>", the output will be"<p>Joel i…</p>".

Newlines in the HTML content will be preserved.

truncatewords

Truncates a string after a certain number of words.

Argument: Number of words to truncate after

For example:

  1. {{ value|truncatewords:2 }}

If value is "Joel is a slug", the output will be "Joel is …".

Newlines within the string will be removed.

truncatewords_html

Similar to truncatewords, except that it is aware of HTML tags. Anytags that are opened in the string and not closed before the truncation point,are closed immediately after the truncation.

This is less efficient than truncatewords, so should only be usedwhen it is being passed HTML text.

For example:

  1. {{ value|truncatewords_html:2 }}

If value is "<p>Joel is a slug</p>", the output will be"<p>Joel is …</p>".

Newlines in the HTML content will be preserved.

unordered_list

Recursively takes a self-nested list and returns an HTML unordered list —WITHOUT opening and closing <ul> tags.

The list is assumed to be in the proper format. For example, if varcontains ['States', ['Kansas', ['Lawrence', 'Topeka'], 'Illinois']], then{{ var|unordered_list }} would return:

  1. <li>States
  2. <ul>
  3. <li>Kansas
  4. <ul>
  5. <li>Lawrence</li>
  6. <li>Topeka</li>
  7. </ul>
  8. </li>
  9. <li>Illinois</li>
  10. </ul>
  11. </li>

upper

Converts a string into all uppercase.

For example:

  1. {{ value|upper }}

If value is "Joel is a slug", the output will be "JOEL IS A SLUG".

urlencode

Escapes a value for use in a URL.

For example:

  1. {{ value|urlencode }}

If value is "https://www.example.org/foo?a=b&c=d&#34;, the output will be"https%3A//www.example.org/foo%3Fa%3Db%26c%3Dd".

An optional argument containing the characters which should not be escaped canbe provided.

If not provided, the '/' character is assumed safe. An empty string can beprovided when all characters should be escaped. For example:

  1. {{ value|urlencode:"" }}

If value is "https://www.example.org/&#34;, the output will be"https%3A%2F%2Fwww.example.org%2F".

urlize

Converts URLs and email addresses in text into clickable links.

This template tag works on links prefixed with http://, https://, orwww.. For example, https://goo.gl/aia1t will get converted butgoo.gl/aia1t won't.

It also supports domain-only links ending in one of the original top leveldomains (.com, .edu, .gov, .int, .mil, .net, and.org). For example, djangoproject.com gets converted.

Links can have trailing punctuation (periods, commas, close-parens) and leadingpunctuation (opening parens), and urlize will still do the right thing.

Links generated by urlize have a rel="nofollow" attribute addedto them.

For example:

  1. {{ value|urlize }}

If value is "Check out www.djangoproject.com", the output will be"Check out <a href="http://www.djangoproject.com&#34;
rel="nofollow">www.djangoproject.com</a>"
.

In addition to web links, urlize also converts email addresses intomailto: links. If value is"Send questions to foo@example.com", the output will be"Send questions to <a href="mailto:foo@example.com">foo@example.com</a>".

The urlize filter also takes an optional parameter autoescape. Ifautoescape is True, the link text and URLs will be escaped usingDjango's built-in escape filter. The default value forautoescape is True.

注解

If urlize is applied to text that already contains HTML markup,things won't work as expected. Apply this filter only to plain text.

urlizetrunc

Converts URLs and email addresses into clickable links just like urlize, buttruncates URLs longer than the given character limit.

Argument: Number of characters that link text should be truncated to,including the ellipsis that's added if truncation is necessary.

For example:

  1. {{ value|urlizetrunc:15 }}

If value is "Check out www.djangoproject.com", the output would be'Check out <a href="http://www.djangoproject.com&#34;
rel="nofollow">www.djangoproj…</a>'
.

As with urlize, this filter should only be applied to plain text.

wordcount

Returns the number of words.

For example:

  1. {{ value|wordcount }}

If value is "Joel is a slug", the output will be 4.

wordwrap

Wraps words at specified line length.

Argument: number of characters at which to wrap the text

For example:

  1. {{ value|wordwrap:5 }}

If value is Joel is a slug, the output would be:

  1. Joel
  2. is a
  3. slug

yesno

Maps values for True, False, and (optionally) None, to the strings"yes", "no", "maybe", or a custom mapping passed as a comma-separated list, andreturns one of those strings according to the value:

For example:

  1. {{ value|yesno:"yeah,no,maybe" }}
ValueArgumentOutputs
True yes
True"yeah,no,maybe"yeah
False"yeah,no,maybe"no
None"yeah,no,maybe"maybe
None"yeah,no"no (converts None to Falseif no mapping for None is given)

Internationalization tags and filters

Django provides template tags and filters to control each aspect ofinternationalization in templates. They allow forgranular control of translations, formatting, and time zone conversions.

i18n

This library allows specifying translatable text in templates.To enable it, set USE_I18N to True, then load it with{% load i18n %}.

See Internationalization: in template code.

l10n

This library provides control over the localization of values in templates.You only need to load the library using {% load l10n %}, but you'll oftenset USE_L10N to True so that localization is active by default.

See Controlling localization in templates.

tz

This library provides control over time zone conversions in templates.Like l10n, you only need to load the library using {% load tz %},but you'll usually also set USE_TZ to True so that conversionto local time happens by default.

See Time zone aware output in templates.

Other tags and filters libraries

Django comes with a couple of other template-tag libraries that you have toenable explicitly in your INSTALLED_APPS setting and enable in yourtemplate with the {% load %} tag.

django.contrib.humanize

A set of Django template filters useful for adding a "human touch" to data. Seedjango.contrib.humanize.

static

static

To link to static files that are saved in STATIC_ROOT Django shipswith a static template tag. If the django.contrib.staticfilesapp is installed, the tag will serve files using url() method of thestorage specified by STATICFILES_STORAGE. For example:

  1. {% load static %}
  2. <img src="{% static "images/hi.jpg" %}" alt="Hi!">

It is also able to consume standard context variables, e.g. assuming auser_stylesheet variable is passed to the template:

  1. {% load static %}
  2. <link rel="stylesheet" href="{% static user_stylesheet %}" type="text/css" media="screen">

If you'd like to retrieve a static URL without displaying it, you can use aslightly different call:

  1. {% load static %}
  2. {% static "images/hi.jpg" as myphoto %}
  3. <img src="{{ myphoto }}">

Using Jinja2 templates?

See Jinja2 for information onusing the static tag with Jinja2.

get_static_prefix

You should prefer the static template tag, but if you need more controlover exactly where and how STATIC_URL is injected into the template,you can use the get_static_prefix template tag:

  1. {% load static %}
  2. <img src="{% get_static_prefix %}images/hi.jpg" alt="Hi!">

There's also a second form you can use to avoid extra processing if you needthe value multiple times:

  1. {% load static %}
  2. {% get_static_prefix as STATIC_PREFIX %}
  3.  
  4. <img src="{{ STATIC_PREFIX }}images/hi.jpg" alt="Hi!">
  5. <img src="{{ STATIC_PREFIX }}images/hi2.jpg" alt="Hello!">

get_media_prefix

Similar to the get_static_prefix, get_media_prefix populates atemplate variable with the media prefix MEDIA_URL, e.g.:

  1. {% load static %}
  2. <body data-media-url="{% get_media_prefix %}">

By storing the value in a data attribute, we ensure it's escaped appropriatelyif we want to use it in a JavaScript context.