def saslprep(data, prohibit_unassigned_code_points=True):
        """An implementation of RFC4013 SASLprep.

        :Parameters:
          - `data`: The string to SASLprep. Unicode strings
            (python 2.x unicode, 3.x str) are supported. Byte strings
            (python 2.x str, 3.x bytes) are ignored.
          - `prohibit_unassigned_code_points`: True / False. RFC 3454
            and RFCs for various SASL mechanisms distinguish between
            `queries` (unassigned code points allowed) and
            `stored strings` (unassigned code points prohibited). Defaults
            to ``True`` (unassigned code points are prohibited).

        :Returns:
        The SASLprep'ed version of `data`.
        """
        if not isinstance(data, _text_type):
            return data

        if prohibit_unassigned_code_points:
            prohibited = _PROHIBITED + (stringprep.in_table_a1,)
        else:
            prohibited = _PROHIBITED

        # RFC3454 section 2, step 1 - Map
        # RFC4013 section 2.1 mappings
        # Map Non-ASCII space characters to SPACE (U+0020). Map
        # commonly mapped to nothing characters to, well, nothing.
        in_table_c12 = stringprep.in_table_c12
        in_table_b1 = stringprep.in_table_b1
        data = u"".join(
            [u"\u0020" if in_table_c12(elt) else elt
             for elt in data if not in_table_b1(elt)])

        # RFC3454 section 2, step 2 - Normalize
        # RFC4013 section 2.2 normalization
        data = unicodedata.ucd_3_2_0.normalize('NFKC', data)

        in_table_d1 = stringprep.in_table_d1
        if in_table_d1(data[0]):
            if not in_table_d1(data[-1]):
                # RFC3454, Section 6, #3. If a string contains any
                # RandALCat character, the first and last characters
                # MUST be RandALCat characters.
                raise ValueError("SASLprep: failed bidirectional check")
            # RFC3454, Section 6, #2. If a string contains any RandALCat
            # character, it MUST NOT contain any LCat character.
            prohibited = prohibited + (stringprep.in_table_d2,)
        else:
            # RFC3454, Section 6, #3. Following the logic of #3, if
            # the first character is not a RandALCat, no other character
            # can be either.
            prohibited = prohibited + (in_table_d1,)

        # RFC3454 section 2, step 3 and 4 - Prohibit and check bidi
        for char in data:
            if any(in_table(char) for in_table in prohibited):
                raise ValueError(
                    "SASLprep: failed prohibited character check")

        return data
An implementation of RFC4013 SASLprep.

        :Parameters:
          - `data`: The string to SASLprep. Unicode strings
            (python 2.x unicode, 3.x str) are supported. Byte strings
            (python 2.x str, 3.x bytes) are ignored.
          - `prohibit_unassigned_code_points`: True / False. RFC 3454
            and RFCs for various SASL mechanisms distinguish between
            `queries` (unassigned code points allowed) and
            `stored strings` (unassigned code points prohibited). Defaults
            to ``True`` (unassigned code points are prohibited).

        :Returns:
        The SASLprep'ed version of `data`.
        
stackoverflow/venv/lib/python3.6/site-packages/pymongo/saslprep.py