How Can I Pivot a Pandas DataFrame Using Different Methods?

How can I pivot a dataframe?

Overview

Pivoting a DataFrame involves rearranging the data to change the orientation of the data. The rows become columns, and the columns become rows. This can be done in several ways, including using the pivot_table, groupby unstack, set_index unstack, pivot, and crosstab methods of Pandas.

Pivot Methods

• pivot_table is a powerful method for pivoting data. It allows you to specify the rows, columns, and values of the pivoted DataFrame, as well as the aggregation function to use.
• groupby unstack is a combination of groupby and unstack methods for creating a data frame. Here, you group data on specific columns and then unstack the level of the new index created by grouping to pivot the data.
• set_index unstack is another useful technique for pivoting data. set_index sets the index of the DataFrame to the specified columns, and unstack changes the current hierarchical index into column headers with the values in the corresponding cells.
• pivot is a scalar method for pivoting data. It should only be used on scalar(one dimensional) valued columns. This method can pivot data frame columns as row index, or row to column matrix values.
• crosstab is a specialized version of the pivot_table for easy creation of cross tabulations using the index/row and columns as row and column headers.

Code demonstration

Below is a simple example of a DataFrame that can be pivoted:

import pandas as pd

# Create a DataFrame name df
df = pd.DataFrame({'Name' : ['Alice', 'Bob', 'Carol', 'Dave'],
                   'Age' : [20, 25, 30, 35],
                   'City' : ['New York', 'Boston', 'Chicago', 'Dallas']})

# Pivot the DataFrame using pivot_table method
df_pivoted = df.pivot_table(index = 'Name', columns = 'City', values = 'Age')

# Display the pivoted DataFrame
print(df_pivoted)

Output :

City    Boston  Chicago  Dallas  New York
Name
Alice    NaN      NaN      NaN       20
Bob      25      NaN      NaN       NaN 
Carol    NaN      30      NaN       NaN 
Dave     NaN      NaN      35       NaN 

Conclusion

The pivot method in pandas is used to transform the data from the long format to the wide format by swapping rows and columns of a data frame. You can select any of the methods explained above according to your need as all these methods are quite useful in making sense of complex level data. I hope it clarified your doubts about data frame pivoting! If you encounter any issues, feel free to continue this discussion.

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