How to add date column in python pandas dataframe

Question

I want to add a date column (from 1/1/1979 upto the data is) in pandas data frame.

Currently, my data frame looks like this:

0   1   2               3           4
0   1   654 31.457899   76.930397   0.2
1   1   711 31.507900   76.880402   0.2
2   1   712 31.507900   76.930397   0.2
3   1   713 31.507900   76.980400   0.2
4   1   714 31.507900   77.030403   0.2
5   1   715 31.507900   77.080399   0.2
6   1   716 31.507900   77.130402   0.2
7   1   717 31.507900   77.180397   0.2
8   1   718 31.507900   77.230400   0.2

Now I want to add one more column of data starting from 1/1/1979. How do I do that?

Answer 1

You can use the built-in date_range function from pandas library to generate dates and then add them to your dataframe. You can use it in the following way:

In [9]: import pandas as pd

In [10]: df = pd.DataFrame({'column1':[34,54,32,23,26]})

In [11]: df
Out[11]: 
   column1
0       34
1       54
2       32
3       23
4       26

In [12]: df['date'] = pd.date_range(start='1/1/1979', periods=len(df), freq='D')

In [13]: df
Out[13]: 
   column1       date
0       34 1979-01-01
1       54 1979-01-02
2       32 1979-01-03
3       23 1979-01-04
4       26 1979-01-05

Here I have incremented the dates day-wise per row. If you want to generate dates in some other way, check out the official documentation here.