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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def clean(s, lowercase=True, replace_by_none=r'[^ \-\_A-Za-z0-9]+', replace_by_whitespace=r'[\-\_]', strip_accents=None, remove_brackets=True, encoding='utf-8', decode_error='strict'):
 """Clean string variables. Clean strings in the Series by removing unwanted tokens, whitespace and brackets. Parameters s : pandas.Series A Series to clean. lower : bool, optional Convert strings in the Series to lowercase. Default True. replace_by_none : str, optional The matches of this regular expression are replaced by ''. replace_by_whitespace : str, optional The matches of this regular expression are replaced by a whitespace. remove_brackets : bool, optional Remove all content between brackets and the bracket themselves. Default True. strip_accents : {'ascii', 'unicode', None}, optional Remove accents during the preprocessing step. 'ascii' is a fast method that only works on characters that have an direct ASCII mapping. 'unicode' is a slightly slower method that works on any characters. None (default) does nothing. encoding : str, optional If bytes are given, this encoding is used to decode. Default is 'utf-8'. decode_error : {'strict', 'ignore', 'replace'}, optional Instruction on what to do if a byte Series is given that contains characters not of the given `encoding`. By default, it is 'strict', meaning that a UnicodeDecodeError will be raised. Other values are 'ignore' and 'replace'. Example ------- 'Bob :)', 'Angel', 'Bob (alias Billy)', None] 0 mary ann 1 bob 2 angel 3 bob 4 NaN dtype: object Returns ------- pandas.Series: A cleaned Series of strings. """


    if s.shape[0] == 0:
        return s

    # Lower s if lower is True
    if lowercase is True:
        s = s.str.lower()

    # Accent stripping based on https://github.com/scikit-learn/
    # scikit-learn/blob/412996f/sklearn/feature_extraction/text.py
    # BSD license
    if not strip_accents:
        pass
    elif callable(strip_accents):
        strip_accents_fn = strip_accents
    elif strip_accents == 'ascii':
        strip_accents_fn = strip_accents_ascii
    elif strip_accents == 'unicode':
        strip_accents_fn = strip_accents_unicode
    else:
        raise ValueError(
            "Invalid value for 'strip_accents': {}".format(strip_accents)
        )

    # Remove accents etc
    if strip_accents:
        def strip_accents_fn_wrapper(x):
            if sys.version_info[0] >= 3:
                if isinstance(x, str):
                    return strip_accents_fn(x)
                else:
                    return x
            else:
                if isinstance(x, unicode):  # noqa
                    return strip_accents_fn(x)
                else:
                    return x

        # encoding
        s = s.apply(
            lambda x: x.decode(encoding, decode_error) if
            type(x) == bytes else x)
        s = s.map(lambda x: strip_accents_fn_wrapper(x))

    # Remove all content between brackets
    if remove_brackets is True:
        s = s.str.replace(r'(\[.*?\]|\(.*?\)|\{.*?\})', '')

    # Remove the special characters
    if replace_by_none:
        s = s.str.replace(replace_by_none, '')

    if replace_by_whitespace:
        s = s.str.replace(replace_by_whitespace, ' ')

    # Remove multiple whitespaces
    s = s.str.replace(r'\s\s+', ' ')

    # Strip s
    s = s.str.lstrip().str.rstrip()

    return s