how to sort the dataframe in python code example

Example 1: sort df by column

df.rename(columns={1:'month'},inplace=True)
df['month'] = pd.Categorical(df['month'],categories=['December','November','October','September','August','July','June','May','April','March','February','January'],ordered=True)
df = df.sort_values('month',ascending=False)

Example 2: sort_values

>>> df.sort_values(by=['col1'])
    col1 col2 col3
0   A    2    0
1   A    1    1
2   B    9    9
5   C    4    3
4   D    7    2
3   NaN  8    4

Example 3: how to sort the dataframe in python

import pandas as pd
df1=pd.read_csv("registration.csv")
df2=pd.read_csv("payment.csv")
df=pd.merge(df1,df2)
print(df.iloc[:,[0,1,3,4]].to_string(index=False))