Examples

import numpy as np
import pandas as pd

df = pd.DataFrame({'c1': [True, True], 'c2': [True, False]})
df

	c1	c2
0	True	True
1	True	False

Default behaviour checks if column-wise values all return True:

df.all()

c1     True
c2    False
dtype: bool

Specify axis='columns' to check if row-wise values all return True:

df.all(axis='columns')

0     True
1    False
dtype: bool

Or axis=None for whether every value is True.