Please note, this is a STATIC archive of website www.w3resource.com from 19 Jul 2022, cach3.com does not collect or store any user information, there is no "phishing" involved.
w3resource

Pandas: Drop a level from a multi-level column index

Pandas Indexing: Exercise-21 with Solution

Write a Pandas program to drop a index level from a multi-level column index of a dataframe.

Note: Levels are 0-indexed beginning from the top.

Sample Solution:

Python Code :

import pandas as pd
cols = pd.MultiIndex.from_tuples([("a", "x"), ("a", "y"), ("a", "z")])
print("\nConstruct a Dataframe using the said MultiIndex levels: ")
df = pd.DataFrame([[1,2,3], [3,4,5], [5,6,7]], columns=cols)
print(df)
#Levels are 0-indexed beginning from the top.
print("\nRemove the top level index:")
df.columns = df.columns.droplevel(0)
print(df)
df = pd.DataFrame([[1,2,3], [3,4,5], [5,6,7]], columns=cols)
print("\nOriginal dataframe:")
print(df)
print("\nRemove the index next to top level:")
df.columns = df.columns.droplevel(1)
print(df)

Sample Output:

Construct a Dataframe using the said MultiIndex levels: 
   a      
   x  y  z
0  1  2  3
1  3  4  5
2  5  6  7

Remove the top level index:
   x  y  z
0  1  2  3
1  3  4  5
2  5  6  7

Original dataframe:
   a      
   x  y  z
0  1  2  3
1  3  4  5
2  5  6  7

Remove the index next to top level:
   a  a  a
0  1  2  3
1  3  4  5
2  5  6  7

Python Code Editor:


Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous: Write a Pandas program to find the indexes of rows of a specified value of a given column in a DataFrame.
Next: Write a Pandas program to insert a column at a specific index in a given DataFrame.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Python: Tips of the Day

Find current directory and file's directory:

To get the full path to the directory a Python file is contained in, write this in that file:

import os 
dir_path = os.path.dirname(os.path.realpath(__file__))

(Note that the incantation above won't work if you've already used os.chdir() to change your current working directory, since the value of the __file__ constant is relative to the current working directory and is not changed by an os.chdir() call.)

To get the current working directory use

import os
cwd = os.getcwd()

Documentation references for the modules, constants and functions used above:

  • The os and os.path modules.
  • The __file__ constant
  • os.path.realpath(path) (returns "the canonical path of the specified filename, eliminating any symbolic links encountered in the path")
  • os.path.dirname(path) (returns "the directory name of pathname path")
  • os.getcwd() (returns "a string representing the current working directory")
  • os.chdir(path) ("change the current working directory to path")

Ref: https://bit.ly/3fy0R6m