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Pandas: Rename names of columns and specific labels of the Main Index of MultiIndex dataframe

Pandas Indexing: Exercise-15 with Solution

Write a Pandas program to rename names of columns and specific labels of the Main Index of the MultiIndex dataframe.

Sample Solution:

Python Code :

import pandas as pd 
import numpy as np
sales_arrays = [['sale1', 'sale1', 'sale2', 'sale2', 'sale3', 'sale3', 'sale4', 'sale4'],
          ['city1', 'city2', 'city1', 'city2', 'city1', 'city2', 'city1', 'city2']]
sales_tuples = list(zip(*sales_arrays))
sales_index = pd.MultiIndex.from_tuples(sales_tuples, names=['sale', 'city'])
print(sales_tuples)
print("\nConstruct a Dataframe using the said MultiIndex levels: ")
df = pd.DataFrame(np.random.randn(8, 5), index=sales_index)
print(df)
print("\nRename the columns name of the said dataframe")
df1 = df.rename(columns={0: "col1", 1: "col2", 2:"col3", 3:"col4", 4:"col5"})
print(df1)
print("\nRename specific labels of the main index of the DataFrame")
df2 = df1.rename(index={"sale2": "S2", "city2": "C2"})
print(df2)

Sample Output:

[('sale1', 'city1'), ('sale1', 'city2'), ('sale2', 'city1'), ('sale2', 'city2'), ('sale3', 'city1'), ('sale3', 'city2'), ('sale4', 'city1'), ('sale4', 'city2')]

Construct a Dataframe using the said MultiIndex levels: 
                    0         1         2         3         4
sale  city                                                   
sale1 city1 -0.846342 -0.741958  1.776873 -0.526789  0.425722
      city2 -1.191729  2.871049  1.334246 -0.555390  0.678033
sale2 city1  1.215433 -0.305873 -0.197025 -1.145550  0.367179
      city2 -1.043111 -0.054862 -0.409382 -0.781236 -1.111498
sale3 city1  0.198136 -0.092846  0.211265 -0.338316 -0.006117
      city2  1.254932  0.660553 -0.343675 -1.488751  1.141144
sale4 city1  0.440996 -1.886134 -1.705170 -0.583568 -0.094108
      city2 -0.645809 -0.979893  0.589839 -0.440143  0.032115

Rename the columns name of the said dataframe
                 col1      col2      col3      col4      col5
sale  city                                                   
sale1 city1 -0.846342 -0.741958  1.776873 -0.526789  0.425722
      city2 -1.191729  2.871049  1.334246 -0.555390  0.678033
sale2 city1  1.215433 -0.305873 -0.197025 -1.145550  0.367179
      city2 -1.043111 -0.054862 -0.409382 -0.781236 -1.111498
sale3 city1  0.198136 -0.092846  0.211265 -0.338316 -0.006117
      city2  1.254932  0.660553 -0.343675 -1.488751  1.141144
sale4 city1  0.440996 -1.886134 -1.705170 -0.583568 -0.094108
      city2 -0.645809 -0.979893  0.589839 -0.440143  0.032115

Rename specific labels of the main index of the DataFrame
                 col1      col2      col3      col4      col5
sale  city                                                   
sale1 city1 -0.846342 -0.741958  1.776873 -0.526789  0.425722
      C2    -1.191729  2.871049  1.334246 -0.555390  0.678033
S2    city1  1.215433 -0.305873 -0.197025 -1.145550  0.367179
      C2    -1.043111 -0.054862 -0.409382 -0.781236 -1.111498
sale3 city1  0.198136 -0.092846  0.211265 -0.338316 -0.006117
      C2     1.254932  0.660553 -0.343675 -1.488751  1.141144
sale4 city1  0.440996 -1.886134 -1.705170 -0.583568 -0.094108
      C2    -0.645809 -0.979893  0.589839 -0.440143  0.032115

Python Code Editor:


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Previous: Write a Pandas program to extract a single row, rows and a specific value from a MultiIndex levels DataFrame.

Next: Write a Pandas program to sort a MultiIndex of a DataFrame. Also sort on various levels of index.

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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