Example of how to subtract by a number the elements of a datafame column with pandas 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
Subtract 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 subtract by 10 the elements of the column b, a solution is to do
>>> df['b'] = df['b'] - 10
>>> df
a b c d
0 1 -8 3 4
1 5 -4 7 8
2 9 0 11 12
References
Links | Site |
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Apply a function to a single column in Dataframe | thispointer.com |
pandas.DataFrame.apply | pandas doc |