create a pandas column label based on a condition in python

To create a pandas column label based on a condition in Python, you can use the np.where() function along with the .rename() method of a DataFrame.

Here's an example code snippet that demonstrates how to do this:

main.py
import pandas as pd
import numpy as np

# Example DataFrame
df = pd.DataFrame({'A': [1, 2, 3, 4, 5]})

# Define the condition
condition = df['A'] > 3

# Create the new column label
new_label = np.where(condition, 'Greater than 3', 'Less than or equal to 3')

# Rename the column
df = df.rename(columns={'A': new_label})

# Output the updated DataFrame
print(df)
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In this example, we start by creating a simple DataFrame with a column labeled 'A'. Then, we define a condition using that column. We use the np.where() function to create the new column label based on the condition. If the condition is True, the new label will be 'Greater than 3', otherwise it will be 'Less than or equal to 3'. Finally, we use the .rename() method to rename the column and update the DataFrame.

Output:

main.py
  Less than or equal to 3
0                    1
1                    2
2                    3
3      Greater than 3
4      Greater than 3
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7 lines

Note that the column label will be changed, but the actual data in the column will remain the same.