Switch between uppercase, lowercase and capitalized file names

convert-case.py

# get the file's location
abs_file_loc = input("\nInput absolute path for the file you want to convert: ")

# open the file, read and return a list containing all lines
with open(abs_file_loc, 'r') as tht:
    input_file = tht.readlines();

# get the line number to conversion
while True:
    line_num = int(input("\nPass the line number you want to convert: "))

    if line_num in range(1, len(input_file)+1): # make sure that the passed line number is in the list containing lines from the file

        # convert line number from human (1 to ...) to python (0 to ...)
        line_num -= 1

        # ask user if he/she has selected proper line
        while True:
            print("Is the line below the line you want to convert? (Y/N):\n\n{}".format(input_file[line_num]))
            permission = input("Answer: ")
            permission = permission.lower()
            # check if answer is 'y' or 'n'
            if permission == 'y' or permission =='n':
                break
        # finish checking if user accept the line or repeat the choosing
        if permission == "y":
            break
        elif permission == "n":
            continue

# select type of conversion
while True:
    convert_mode = int(input("""
Choose the mode of conversion:
    [1] lowercase
    [2] UPPERCASE
    [3] Capitalized
Mode: """))

    if convert_mode in range(1, 4):
        break

# convert the line
if convert_mode == 1:
    input_file[line_num] = input_file[line_num].lower()
elif convert_mode == 2:
    input_file[line_num] = input_file[line_num].upper()
else:
    input_file[line_num] = input_file[line_num].capitalize()

# replace the original line with converted one
with open(abs_file_loc, 'w') as output_file:
    output_file.writelines(input_file)

print("\nFinished.")