Reading and writing with files in python?

def sum_column(filename):
total, error_count = 0, 0
with open(filename, 'r') as file:
for line in file:
try:
total += int(line.strip())
except ValueError:
error_count += 1
return total, error_count

def sum_all(filename):
total, error_count = 0, 0
with open(filename, 'r') as file:
for line in file:
for num in line.split():
try:
total += int(num)
except ValueError:
error_count += 1
return total, error_count

def main():
filename = input("Enter a file name: ")
operation = input("Enter operation (sum_column or sum_all): ")

try: if operation == "sum_column": result, errors = sum_column(filename) print(f"Sum: {result}, Errors: {errors}") elif operation == "sum_all": result, errors = sum_all(filename) print(f"Sum: {result}, Errors: {errors}") else: print("Invalid operation entered.") except FileNotFoundError: print(f"User-friendly message: The file '{filename}' does not exist.") 

if name == "main":
main()