Read a file containing integer and return the average of the integer in the file. the file can have path to another file which contain integer.

a_file.txt

1
2
3
4
5
another_file.txt
3
4
5
6

another_file.txt

10
11
12
13
14
the_third_file.txt

main.py

def read_file_recursively(filename):
    """
    Read a file recursively and return the
     sum and the count of integer in the file
    
    Args:
        filename ([string]): path to the base file to read
    
    Returns:
        [tuple]: sum of all items in the list,  the number of items
    """
    sum_, len_ = 0, 0
    with open(filename, 'r') as the_file:
        for line in the_file.readlines():
            try:
                sum_ += int(line)
                len_ +=1
            except ValueError:
                sub_sum, sub_leng = read_file_recursively(line.strip())
                sum_ += sub_sum
                len_ += sub_leng
    return sum_, len_

if __name__ == "__main__":
    sum_, len_ = read_file_recursively('a_file.txt')
    print('the average is : ', sum_/len_)

the_third_file.txt

40
50
60
70
80