add weekday names to a csv file

convert.py

import pandas as pd

df = pd.read_csv('message.csv', dtype=str)

# rename columns to lower case and replace spaces with underscores
columns = {col: col.lower().replace(' ', '_').replace('/','_') for col in list(df.columns)}
df.rename(columns, axis=1, inplace=True)

for col in list(df.columns):
    # Ensuring that the column is always a string without spaces before or after
    df[col] = df[col].astype(str).str.strip()
  
    # in case this look like str formatted date (eg 02/12/2020)
    if df[col].str.match("\d{2}/\d{2}/\d{4}", case=True).all():
        # # convert to date
        df[col] = pd.to_datetime(df[col], format="%d/%m/%Y")
        # finding the index for the current column
        index = list(df.columns).index(col)
        # add new column as weekday name after the current column
        df.insert(loc=index+1, column=f"{col}_weekday", value=df[col].dt.day_name())
    
# Save the file
df.to_csv('message_cleaned.csv', index=False)