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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 category_replace(text, replacements=UNICODE_CATEGORIES):
 """Remove characters from a string based on unicode classes. This is a method for removing non-text characters (such as punctuation, whitespace, marks and diacritics) from a piece of text by class, rather than specifying them individually. """

    if text is None:
        return None
    characters = []
    for character in decompose_nfkd(text):
        cat = category(character)
        replacement = replacements.get(cat, character)
        if replacement is not None:
            characters.append(replacement)
    return u''.join(characters)