Question

我有一个数据框

data = {'A':['a','a',3,3,'c','c'],'B': [0, .5, 101, 105, 2000, 2500]}
df = pd.DataFrame(data, columns = ['A','B'])

和字典

d = {'a':['a',3,'c'],'b':[5,200,3000],'c':[1,2,3]}

我想使用d['a']与df['A']进行比较，如果相等，则将d['b']到df['B']的值添加到新列df['C']中结果将是

data2 = {'A':['a','a','b','b','c','c'],'B': [0, .5, 101, 105, 2000, 2500],'C':[5,5.5,301,305,5000,5500]}
df2 = pd.DataFrame(data2, columns = ['A','B','C'])

Answer 1

另一种方法是构造一个普通地图：

import pandas as pd

data = {'A':['a','a',3,3,'c','c','d'],'B': [0, .5, 101, 105, 2000, 2500, 3000]}
df = pd.DataFrame(data, columns = ['A','B'])

m = dict(zip(d['a'],d['b']))
df['C'] = df['B'] + df['A'].map(m).fillna(0)  # Fillna to avoid Not A Number (NaN

print(df)

返回：

   A       B       C
0  a     0.0     5.0
1  a     0.5     5.5
2  3   101.0   301.0
3  3   105.0   305.0
4  c  2000.0  5000.0
5  c  2500.0  5500.0
6  d  3000.0  3000.0

如何将python dict的值关联到pandas数据框

1 个答案: