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Pandas: Split the specified dataframe into groups based on first column and set other column values into a list of values

Pandas Grouping and Aggregating: Split-Apply-Combine Exercise-13 with Solution

Write a Pandas program to split the following dataframe into groups based on first column and set other column values into a list of values.

Test Data:

    X   Y   Z
0  10  10  22
1  10  15  20
2  10  11  18
3  20  20  20
4  30  21  13
5  30  12  10
6  10  14   0

Sample Solution:

Python Code :

import pandas as pd
df = pd.DataFrame( {'X' : [10, 10, 10, 20, 30, 30, 10], 
                    'Y' : [10, 15, 11, 20, 21, 12, 14], 
                    'Z' : [22, 20, 18, 20, 13, 10, 0]})
print("Original DataFrame:")
print(df)
result= df.groupby('X').aggregate(lambda tdf: tdf.unique().tolist())
print(result)

Sample Output:

Original DataFrame:
    X   Y   Z
0  10  10  22
1  10  15  20
2  10  11  18
3  20  20  20
4  30  21  13
5  30  12  10
6  10  14   0
                   Y                Z
X                                    
10  [10, 15, 11, 14]  [22, 20, 18, 0]
20              [20]             [20]
30          [21, 12]         [13, 10]

Python Code Editor:


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Previous: Write a Pandas program to split the following dataframe into groups, group by month and year based on order date and find the total purchase amount year wise, month wise.
Next: Write a Pandas program to split the following dataframe into groups based on all columns and calculate Groupby value counts on the dataframe.

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