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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 escape_unicode_string(u):
 """ Escapes the nonprintable chars 0-31 and 127, and backslash; preferably with a friendly equivalent such as '\n' if available, but otherwise with a Python-style backslashed hex escape. """

    def replacer(matchobj):
        if ord(matchobj.group(1)) == 127:
            return "\\x7f"
        if ord(matchobj.group(1)) == 92: # backslash
            return "\\\\"
        return REPLACEMENT_TABLE[ord(matchobj.group(1))]
    return re.sub("([\\000-\\037\\134\\177])", replacer, u)