Get first letter of a string from column

Question

I\'m fighting with pandas and for now I\'m loosing. I have source table similar to this:

import pandas as pd

a=pd.Series([123,22,32,453,45,453,56])
b=pd.Ser         


        

Answer 1

Cast the dtype of the col to str and you can perform vectorised slicing calling str:

In [29]:
df['new_col'] = df['First'].astype(str).str[0]
df

Out[29]:
   First  Second new_col
0    123     234       1
1     22    4353       2
2     32     355       3
3    453     453       4
4     45     345       4
5    453     453       4
6     56      56       5

if you need to you can cast the dtype back again calling astype(int) on the column