def connect_bases(char1, char2):
    """
    For two aligned bases, get connecting symbol.
    Bases on whether bases match, mismatch or are part of a gap.

    Args:
        char1, char2 (str): Two aligned bases.
    """
    if char1 == '-' or char2 == '-':
        return ' '
    if char1 == char2:
        return '|'
    return '.'