How to rename a CSV file by adding MODIFIED in the filename?

[Larz60+]

Just to clarify:

In the original code (posted below again), parts was used to create the output file name, and had nothing to do with input file name (as requested by member). There are several ways to do this, I chose splitting into parts, adding in 'Modified' to end of filename, and joining back together.

Original code:

import csv
from pathlib import Path
from tkinter.filedialog import askopenfilename
import sys
 
 
def read_csv_file(filename):
    parts = list(filename.parts)
    parts[-1] = f"{filename.stem}Modified{filename.suffix}"
    parts[0] = ''
    outfilename = Path(f"{'/'.join(parts)}")
 
    print(f"new output file name: {outfilename}")
 
    with filename.open() as fp, outfilename.open('w') as fout:
        crdr = csv.reader(fp, delimiter=',')
        cwrtr = csv.writer(fout, delimiter=',')
        for row in crdr:
            print(row)
            # Modify row as desired here
            cwrtr.writerow(row)
 
def get_filename():
    badcount = 0
 
    while(True):
        try:
            if badcount > 2:
                print("Three strikes and your out!")
                sys.exit(-1)
            filename = Path(askopenfilename(filetypes=[("CSV files","*.csv")]))
            break
        except TypeError:
            badcount += 1
            print(f"bad filename, try again")
         
    return filename
 
 
if __name__ == '__main__':
    read_csv_file(get_filename())

Please note f-strings are not being properly displayed. items within brackets should be highlighted as they are placeholders for the variable they contain.