熊猫数据框列的字典

Question

How to create a dictionary from columns of pandas dataframe. here is test code:

import pandas as pd
df = pd.DataFrame({
    'c0': ['A','A','B'],
    'c1': ['b','c','d'],
    'c2': [1, 3,4],
    'c3': [5,7,8]})

Output:

  c0 c1  c2  c3
0  A  b   1   5
1  A  c   3   7
2  B  d   4   8

I would like to obtain a dictionary from, say, key:(c0, c1) and value:(c2)

{('A', 'b'): 1, ('A', 'c'): 3, ('B', 'd'): 4}

Answer 1

You can use set_index with Series.to_dict - MutiIndex creates tuples :

print (df.set_index(['c0','c1'])['c2'].to_dict())
{('B', 'd'): 4, ('A', 'b'): 1, ('A', 'c'): 3}

Answer 2

这是我做的

dict(zip(zip(df['c0'], df['c1']), df['c2']))