def read_file_list(filename):
    """Read file and print out each line separately with a "-" before it.

    For example, if we have a file, `dogs`, containing:
        Fido
        Whiskey
        Dr. Sniffle

    This should work:

        >>> read_file_list("fs_5_cats")
        - Fido
        - Whiskey
        - Dr. Sniffle

    It will raise an error if the file cannot be found.
    """

    # hint: when you read lines of files, there will be a "newline"
    # (end-of-line character) at the end of each line, and you want to
    # strip that off before you print it. Do some research on that!

    f = None

    try:
        f = open(filename, 'r')
        for r in f:
            r = r.rstrip()
            print(f"- {r}")
    finally:
        if f:
            f.close()

read_file_list("fs_5_cats")