def b32decode(s, casefold=False, map01=None):
    quanta, leftover = divmod(len(s), 8)
    if leftover:
        raise TypeError('Incorrect padding')
    # Handle section 2.4 zero and one mapping.  The flag map01 will be either
    # False, or the character to map the digit 1 (one) to.  It should be
    # either L (el) or I (eye).
    if map01:
        s = _translate(s, {'0': 'O', '1': map01})
    if casefold:
        s = s.upper()
    # Strip off pad characters from the right.  We need to count the pad
    # characters because this will tell us how many null bytes to remove from
    # the end of the decoded string.
    padchars = 0

    # Replace regex code
    #mo = re.search('(?P<pad>[=]*)$', s)
    #if mo:
    #    padchars = len(mo.group('pad'))
    #    if padchars > 0:
    #        s = s[:-padchars]
    # Replace with:
    padchars = len(s)
    s = s.rstrip('=')
    padchars -= len(s)

    # Now decode the full quanta
    parts = []
    acc = 0
    shift = 35
    for c in s:
        val = _b32rev.get(c)
        if val is None:
            raise TypeError('Non-base32 digit found')
        #acc += _b32rev[c] << shift
        acc += _b32rev[c] * (2**shift)
        shift -= 5
        if shift < 0:
            parts.append(binascii.unhexlify('%010x' % acc))
            acc = 0
            shift = 35
    # Process the last, partial quanta
    last = binascii.unhexlify('%010x' % acc)
    if padchars == 0:
        last = ''                       # No characters
    elif padchars == 1:
        last = last[:-1]
    elif padchars == 3:
        last = last[:-2]
    elif padchars == 4:
        last = last[:-3]
    elif padchars == 6:
        last = last[:-4]
    else:
        raise TypeError('Incorrect padding')
    parts.append(last)
    return EMPTYSTRING.join(parts)



# RFC 3548, Base 16 Alphabet specifies uppercase, but hexlify() returns
# lowercase.  The RFC also recommends against accepting input case
# insensitively.
Decode a Base32 encoded string.
dataset/ETHPy150Open anandology/pyjamas/pyjs/src/pyjs/lib/base64.py/b32decode