write code that resides in parent directory

[franklin97355]

New to Python and have a question on usage. I am using Linux. I have a Python 3.11 program that reads, parses, and writes an ics file that works if it is in the same directory as the files. I would like to have it not have to be in the same directory but in the parent directory. Any insights are welcome.

from pathlib import Path
ROOT_DIR = Path(__file__).parent
ics_file = input('\n ics file name?')
if('.ics'not in ics_file):
        ics_file = ics_file + ".ics"
output_file = input('\n csv file name?')
if('.csv'not in output_file):
        output_file = output_file + ".csv"
date_range = input('\n date range (YYYYMM)')
INPUT_FILE = ROOT_DIR / ics_file
OUTPUT_FILE = ROOT_DIR / output_file
print(ROOT_DIR)
print(INPUT_FILE)
print(OUTPUT_FILE)
print(ROOT_DIR.parent)
if not INPUT_FILE.exists():
        print("ICS file not found")

TARGET_LINE = 'SUMMARY:'
DATE_LINE = 'DTSTART;VALUE=DATE:'

fp = open(OUTPUT_FILE,"w")
output_lines = []    
contents = INPUT_FILE.read_text().strip().splitlines()

for line_num, line in enumerate(contents, 1):
    if line.startswith(DATE_LINE):
        y = line.strip(DATE_LINE)
       
    elif line.startswith(TARGET_LINE):
        x = line.strip(TARGET_LINE)
        if(date_range in y):
            fp.write(str(y)+", ")
            fp.write(x)
            fp.write("\n")   
       
print('DONE')