如何将 Python 中 DataFrame 中的行转换为字典

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时间:2020-08-19 09:49:06  来源:igfitidea点击:

How to convert rows in DataFrame in Python to dictionaries

pythondictionarypandas

提问by Vicky

For example, I have DataFrame now as

例如,我现在有 DataFrame 作为

id score1   score2  score3  score4  score5
1  0.000000     0.108659    0.000000    0.078597    1
2  0.053238     0.308253    0.286353    0.446433    1
3  0.000000     0.083979    0.808983    0.233052    1

I want to convert it as

我想将其转换为

id scoreDict
1  {'1': 0, '2': 0.1086, ...}
2  {...}
3  {...}

Anyway to do that?

无论如何要这样做?

Thanks in advance!

提前致谢!

采纳答案by Jianxun Li

import pandas as pd

# your df
# =========================
print(df)

   id  score1  score2  score3  score4  score5
0   1  0.0000  0.1087  0.0000  0.0786       1
1   2  0.0532  0.3083  0.2864  0.4464       1
2   3  0.0000  0.0840  0.8090  0.2331       1

# to_dict
# =========================
df.to_dict(orient='records')

Out[318]: 
[{'id': 1.0,
  'score1': 0.0,
  'score2': 0.10865899999999999,
  'score3': 0.0,
  'score4': 0.078597,
  'score5': 1.0},
 {'id': 2.0,
  'score1': 0.053238000000000001,
  'score2': 0.308253,
  'score3': 0.28635300000000002,
  'score4': 0.44643299999999997,
  'score5': 1.0},
 {'id': 3.0,
  'score1': 0.0,
  'score2': 0.083978999999999998,
  'score3': 0.80898300000000001,
  'score4': 0.23305200000000001,
  'score5': 1.0}]

回答by oldmonk

I think the below code will give you the data frame in the format you are looking for. Also it allows you to choose any column as an index

我认为下面的代码将为您提供您正在寻找的格式的数据框。它还允许您选择任何列作为索引

import pandas as pd

#IMPORT YOUR DATA
#Any other way to import data can also be used. I saved it in .csv file 
df=pd.read_csv('dftestid.csv')
print("INITIAL DATAFRAME")
print(df)
print()

#Convert Data Frame to Dictionary (set_index method allows any column to be used as index)
df2dict=df.set_index('id').transpose().to_dict(orient='dict')


#Convert Dictionary to List with 'score' replaced
dicttolist=[[k,{int(k1.replace('score','')):v1 for k1,v1 in v.items()}] for k,v in df2dict.items()]

#"Create the new DataFrame"

df2=pd.DataFrame(dicttolist,columns=['id', 'scoreDict'])
print("NEW DATAFRAME")
print(df2)


OUT:
INITIAL DATAFRAME
   id    score1    score2    score3    score4  score5
0   1  0.000000  0.108659  0.000000  0.078597       1
1   2  0.053238  0.308253  0.286353  0.446433       1
2   3  0.000000  0.083979  0.808983  0.233052       1

NEW DATAFRAME
   id                                          scoreDict
0   1  {1: 0.0, 2: 0.108659, 3: 0.0, 4: 0.078597, 5: ...
1   2  {1: 0.053238, 2: 0.308253, 3: 0.286353, 4: 0.4...
2   3  {1: 0.0, 2: 0.083979, 3: 0.808983, 4: 0.233052...

回答by Adav

For others like me coming to this question but looking to do the following: Create a dict row by row to map a column based of the value of the adjacent column.

对于像我这样遇到这个问题但希望执行以下操作的其他人:逐行创建一个 dict 以根据相邻列的值映射一列。

Here's our mapping table:

这是我们的映射表:

  Rating    y
0  AAA      19
1  AA1      18
2  AA2      17
3  AA3      16
4  A1       15
5  A2       14
6  A3       13
      ...
19 D       0

IN:

在:

import pandas as pd
df_map.set_index('y')
df_map.transpose()
dict_y = df_map['Rating'].to_dict()

OUT:

出去:

{19: 'AAA',
 18: 'AA1',
 17: 'AA2',
 16: 'AA3',
 15: 'A1',
 14: 'A2',
 13: 'A3',
 12: 'BBB1',
 11: 'BBB2',
 10: 'BBB3',
 9: 'BB1',
 8: 'BB2',
 7: 'BB3',
 6: 'B1',
 5: 'B2',
 4: 'B3',
 3: 'CCC1',
 2: 'CCC2',
 1: 'D'}

回答by alienzj

df = pd.DataFrame({'col1': [1, 2],
                   'col2': [0.5, 0.75]},
                   index=['row1', 'row2'])
df
      col1  col2
row1    1   0.50
row2    2   0.75

df.to_dict(orient='index')
{'row1': {'col1': 1, 'col2': 0.5}, 'row2': {'col1': 2, 'col2': 0.75}}