Uniqify

The Python version is neat in that it's entirely type agnostic as long asthe value supports hashing.I'm sure it's possible to do an equivalent one in Go using interface{}.Patches welcome.

For faster variants in Python seeFastest way to uniqify a list inPython.

For some more thoughts on this, and an example of a implementationthat is not in-place check out this mailing listthread.

Python

  1. def uniqify(seq):
  2.     seen = {}
  3.     unique = []
  4.     for item in seq:
  5.         if item not in seen:
  6.             seen[item] = 1
  7.             unique.append(item)
  8.     return unique
  9.  
  10. items = ['B', 'B', 'E', 'Q', 'Q', 'Q']
  11. print uniqify(items)  # prints ['B', 'E', 'Q']

Go

  1. package main
  2.  
  3. import "fmt"
  4.  
  5. func uniqify(items *[]string) {
  6.     seen := make(map[string]bool)
  7.     j := 0
  8.     for i, x := range *items {
  9.         if !seen[x] {
  10.             seen[x] = true
  11.             (*items)[j] = (*items)[i]
  12.             j++
  13.         }
  14.     }
  15.     *items = (*items)[:j]
  16. }
  17.  
  18. func main() {
  19.     items := []string{"B", "B", "E", "Q", "Q", "Q"}
  20.     uniqify(&items)
  21.     fmt.Println(items) // prints [B E Q]
  22. }