Open many files - exception handling

---

examples/files/average_from_files.py

import sys


def main():
    for filename in sys.argv[1:]:
        try:
            do_some_stuff(filename)
        except Exception as err:
            print(f"trouble with '{filename}': Error: {err}")

def do_some_stuff(filename):
    with open(filename) as fh:
        total = 0
        count = 0
        for line in fh:
            number = float(line)
            total += number
            count += 1
        print("Average: ", total/count)

main()

examples/files/number_per_line.txt

23
1
192
17

examples/files/empty.txt

examples/files/number_per_line2.txt

1
2
3
4
5
6

$ python average_from_files.py number_per_line.txt empty.txt number_per_line2.txt

Average:  58.25
trouble with 'empty.txt': Error: division by zero
Average:  3.5

$ python average_from_files.py numbers.txt

trouble with 'numbers.txt': Error: could not convert string to float: '23 345 12345\n'

$ python average_from_files.py more_numbers.txt

trouble with 'more_numbers.txt': Error: [Errno 2] No such file or directory: 'more_numbers.txt'