筛选Pandas数据帧时出现问题

举一个这样的例子:

df = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]})
>>> df
   A  B
0  1  4
1  2  5
2  3  6

# df!=True checks for each value in the DataFrame if the value is equal to True (it matches on 1 because 1 is equivalent to True (and False equivalent to 0) when using "==" and "!="
>>> df!=True 
       A     B
0  False  True
1   True  True
2   True  True

# df[df!=True] gets the values which are True in df!=True, and doesn't get anything for the ones which are false (hence A0 being NaN)
>>> df[df!=True]
     A  B
0  NaN  4
1  2.0  5
2  3.0  6

# this is similar to example #1, but only looks at column 'A'
>>> df['A']!=True
0    False
1     True
2     True
Name: A, dtype: bool

筛选到列“A”==为True的行

>>> df[df['A']!=True]
   A  B
1  2  5
2  3  6

Pandas会在您想要筛选行时插入它,因此它会采用上一个示例中的值,并将行筛选为返回True的行。如果您只想要实际为True的值(即不匹配 1 s) ,您可以使用 is ,如

1 is True # False