def clean_string(string: str) -> str:
    """
    Removes control characters from a string.
    >>> clean_string('This is a sentence\\r with newline.')
    'This is a sentence with newline'
    >>> clean_string('')
    ''
    >>> clean_string('  This is  a sentence\\r with. newline.  ')
    'This is  a sentence with. newline'
    """
    return string \
        .replace('\n', '') \
        .replace('\r', '') \
        .replace('\t', '') \
        .replace('\f', '') \
        .replace('\0', '') \
        .strip(' ') \
        .strip('.')