rename a column in pandas based on str.contains in python

main.py
import pandas as pd

# create a sample dataframe
df = pd.DataFrame({'col1': [1, 2, 3],
                   'col2_a': [4, 5, 6],
                   'col2_b': [7, 8, 9],
                   'col3': [10, 11, 12]})

# create a dictionary to map the old column names to new column names
new_names = {}
for col in df.columns:
    if 'col2' in col:
        new_names[col] = 'new_col2_name'
    else:
        new_names[col] = col

# rename the columns using the dictionary
df = df.rename(columns=new_names)

print(df)
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main.py
   col1  new_col2_name  new_col2_name  col3
0     1              4              7    10
1     2              5              8    11
2     3              6              9    12
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