pandas sort alphabetically by column code example

Example 1: sort a dataframe by a column valuepython

>>> 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 2: sort dataframe by column

df.sort_values(by='col1', ascending=False)

Example 3: pandas reorder columns by name

#old df columns
df.columns
Index(['A', 'B', 'C', 'D'],dtype='***')
#new column format that we want to rearange
new_col = ['D','C','B','A'] #list of column name in order that we want

df = df[new_col]
df.columns
Index(['D', 'C', 'B', 'A'],dtype='***')
#new column order

Example 4: 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))