Fix Python – Shift column in pandas dataframe up by one?

Question

Asked By – natsuki_2002

I’ve got a pandas dataframe. I want to ‘lag’ one of my columns. Meaning, for example, shifting the entire column ‘gdp’ up by one, and then removing all the excess data at the bottom of the remaining rows so that all columns are of equal length again.

df =
    y  gdp  cap
0   1    2    5
1   2    3    9
2   8    7    2
3   3    4    7
4   6    7    7

df_lag =
    y  gdp  cap
0   1    3    5
1   2    7    9
2   8    4    2
3   3    7    7

Anyway to do this?

Now we will see solution for issue: Shift column in pandas dataframe up by one?


Answer

In [44]: df['gdp'] = df['gdp'].shift(-1)

In [45]: df
Out[45]: 
   y  gdp  cap
0  1    3    5
1  2    7    9
2  8    4    2
3  3    7    7
4  6  NaN    7

In [46]: df[:-1]                                                                                                                                                                                                                                                                                                               
Out[46]: 
   y  gdp  cap
0  1    3    5
1  2    7    9
2  8    4    2
3  3    7    7

This question is answered By – Wouter Overmeire

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