def create_modified_file(input_file, output_file):
    """ (file, file) -> tuple 

    For text file <input_file>, creates a new version in file <output_file>
    in which all instances of the letter 'e' are removed

    Returns a tuple containing how many occurences of letter 'e' were removed,
    and the total character count of the file (num_total, num_removals)
    """
    # Init
    empty_str = ''
    num_total_chars = 0
    num_removals = 0

    for line in input_file:
        # Save original line length
        orig_line_length = len(line) - 1
        num_total_chars += orig_line_length # Track No. chars in file
        # Remove all occurrences of letter'e'
        modified_line = line.replace('e', empty_str).replace('E', empty_str)
        num_removals += orig_line_length - (len(modified_line) - 1) # Track No. chars removed
        # Simultaneously output line to screen and outpyr file
        print(modified_line.strip('\n'))
        output_file.write(modified_line)
    return (num_total_chars, num_removals)