Examples
Checks for Alphabetic and Numeric Characters

In [1]:
import numpy as np
import pandas as pd
In [2]:
s1 = pd.Series(['two', 'two2', '2', ''])
In [3]:
s1.str.isalpha()
Out[3]:
0     True
1    False
2    False
3    False
dtype: bool
In [4]:
s1.str.isnumeric()
Out[4]:
0    False
1    False
2     True
3    False
dtype: bool
In [5]:
s1.str.isalnum()
Out[5]:
0     True
1     True
2     True
3    False
dtype: bool

Note that checks against characters mixed with any additional punctuation or whitespace
will evaluate to false for an alphanumeric check.

In [6]:
s2 = pd.Series(['P Q', '2.5', '2,000'])
s2.str.isalnum()
Out[6]:
0    False
1    False
2    False
dtype: bool