1import pandas as pd
2
3df = pd.DataFrame({'A': [1, None, 'hello', True, 'world', 'mystr', 34.11]})
4
5df['stringy'] = [isinstance(x, str) for x in df.A]
6
7# A stringy
8# 0 1 False
9# 1 None False
10# 2 hello True
11# 3 True False
12# 4 world True
13# 5 mystr True
14# 6 34.11 False