How to divide by a number the elements of a pandas data frame column in python ?

How to divide by a number the elements of a pandas data frame column in python ?

Daidalos April 14, 2020


Example of how to divide by a number the elements of a pandas data frame column in python ?

Create a simple Data frame

Let's create a data frame with pandas called df:

>>> import pandas as pd
>>> import numpy as np
>>> data = np.arange(1,13)
>>> data = data.reshape(3,4)
>>> df = pd.DataFrame(data=data,columns=['a','b','c','d'])
>>> df
   a   b   c   d
0  1   2   3   4
1  5   6   7   8
2  9  10  11  12

Divide by a number the elements of a given column

Let's select the column b for example:

>>> df['b']
0     2
1     6
2    10

to divide by 2 each element of the column b, a solution is to do:

>>> df['b'] = df['b']  / 2.0
>>> df
   a    b   c   d
0  1  1.0   3   4
1  5  3.0   7   8
2  9  5.0  11  12

References

Links Site
Apply a function to a single column in Dataframe thispointer.com
pandas.DataFrame.apply pandas doc