check if dataframe is of boolean type pandas

Question

I have a pandas DataFrame as below:

In [108]: df1
Out[108]: 
                         v
t                         
2014-02-21 10:30:43  False
2014-02-21 10:31:34  False
2014-02-21 10:32:25  False
2014-02-21 10:33:17  False
2014-02-21 10:34:09  False
2014-02-21 10:35:00  False
2014-02-21 10:35:51  False

I need to check if the dtype of this dataframe is bool. I tried with:

In [109]: print isinstance(df1, bool)
False

**It should return **True****

How can I do this?

Reference: check if variable is dataframe

Answer 1

You can print the dtypes of the columns:

In [2]:

import pandas as pd

df = pd.DataFrame({'a':[True,False,False]})
df
Out[2]:
       a
0   True
1  False
2  False

[3 rows x 1 columns]

In [3]:

df.dtypes

Out[3]:
a    bool
dtype: object
In [4]:

df.a.dtypes
Out[4]:
dtype('bool')

So in your case df1.v.dtypes should print the same output as above

The other thing to note that isinstance(df, bool) will not work as it is a pandas dataframe or more accurately:

In [7]:

type(df)
Out[7]:
pandas.core.frame.DataFrame

The important thing to note is that dtypes is in fact a numpy.dtype you can do this to compare the name of the type with a string but I think isinstance is clearer and preferable in my opinion:

In [13]:

df.a.dtypes.name == 'bool'
Out[13]:
True