CODEWITHSUNDEEP
pythonpandassortingdataframe
Quant Christo
Quant Christo

Reputation: 1430

How to change column order (sort) in pandastic way?

I have a dataframe with header that is list of 'string-integers':

import pandas as pd

d = {'1': [1, 2], '7': [3, 4], '3': [3, 4], '5': [2, 7]}
df = pd.DataFrame(data=d)

   1  3  5  7
0  1  3  2  3
1  2  4  7  4

This code change order of column (sort):

cols = df.columns.tolist()
cols = [int(x) for x in cols]
cols.sort()
cols = [str(x) for x in cols]
df = df[cols]

   1  3  5  7
0  1  3  2  3
1  2  4  7  4

I'm not happy with this solution. Of course, I can hide it in the function, but probably more elegant approach exist.

Upvotes: 1

Views: 127

Answers (1)

jpp
jpp

Reputation: 164773

There are several options depending on what you require.

Option 1

You can use sort_values to sort as strings:

df.columns = df.columns.sort_values()

Note this means that "10" will appear before "2".

Option 2

If you wish to convert to integers and then sort:

df.columns = df.columns.astype(int).sort_values()

Option 3

If you want to keep as string, but order by integer value:

df.columns = df.columns.astype(int).sort_values().astype(str)

A pure Python approach is also possible:

df.columns = sorted(df, key=int)

Upvotes: 1

Related Questions