创建示例数据

To create a dataframe from every combination of some given values, like R’s expand.grid() function, we can create a dict where the keys are column names and the values are lists of the data values:

  1. In [195]: def expand_grid(data_dict):
  2.    .....:    rows = itertools.product(*data_dict.values())
  3.    .....:    return pd.DataFrame.from_records(rows, columns=data_dict.keys())
  4.    .....: 
  6. In [196]: df = expand_grid(
  7.    .....:    {'height': [60, 70],
  8.    .....:     'weight': [100, 140, 180],
  9.    .....:     'sex': ['Male', 'Female']})
  10.    .....: 
  12. In [197]: df
  13. Out[197]: 
  14.     height  weight     sex
  15. 0       60     100    Male
  16. 1       60     100  Female
  17. 2       60     140    Male
  18. 3       60     140  Female
  19. 4       60     180    Male
  20. 5       60     180  Female
  21. 6       70     100    Male
  22. 7       70     100  Female
  23. 8       70     140    Male
  24. 9       70     140  Female
  25. 10      70     180    Male
  26. 11      70     180  Female