应用groupby和size后，Python pandas访问True和False值

Question

I have a dataframe with a column named diff. I am able to group this column and get the number of True and False occurrences in the data frame.

df.groupby('diff').size()

returns

diff
True    5101
False     61
dtype: int64

I want to access to the value of True , 5101 .

I have already tried

df.groupby('diff').size().loc['True']

Answer 1

It is Series , so loc should be omit:

s = pd.Series([5101, 61], index=[True, False])
print (s)
True     5101
False      61
dtype: int64

print (s[True])
5101

Answer 2

The answer is:

df_merged.groupby('diff').size().loc[True]

Explanation: note that

df_merged.groupby('diff').size().index

returns

Index([True, False], dtype='object', name='diff')

It's a bool True , not a "True" like in a string !!!!

Answer 3

在lambda使用.loc

s = df.groupby('diff').size().loc[lambda x :x]