Python – Stacking a single-level column with Pandas stack()?

To stack a single-level column, use the datafrem.stack(). At first, let us import the required library −

import pandas as pd

Create a DataFrame with single-level column −

dataFrame = pd.DataFrame([[10, 15], [20, 25], [30, 35], [40, 45]],index=['w', 'x', 'y', 'z'],columns=['a', 'b'])

Stack the DataFrame using the stack() method −

dataFrame.stack()

Example

Following is the complete code −

import pandas as pd

# Create DataFrame
dataFrame = pd.DataFrame([[10, 15], [20, 25], [30, 35], [40, 45]],index=['w', 'x', 'y', 'z'],columns=['a', 'b'])

# DataFrame
print"DataFrame...\n",dataFrame

# stack
print"\nStacking...\n",dataFrame.stack()

Output

This will produce the following output −

DataFrame...
    a   b
w  10  15
x  20  25
y  30  35
z  40  45

Stacking...
w  a    10
   b    15
x  a    20
   b    25
y  a    30
   b    35
z  a    40
   b    45
dtype: int64