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53a51b3529
* rewrite of base32.py * changed maps to list comprehension * Apply suggestions from code review Co-authored-by: Tianyi Zheng <tianyizheng02@gmail.com> --------- Co-authored-by: Tianyi Zheng <tianyizheng02@gmail.com>
46 lines
1.4 KiB
Python
46 lines
1.4 KiB
Python
"""
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Base32 encoding and decoding
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https://en.wikipedia.org/wiki/Base32
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"""
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B32_CHARSET = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567"
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def base32_encode(data: bytes) -> bytes:
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"""
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>>> base32_encode(b"Hello World!")
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b'JBSWY3DPEBLW64TMMQQQ===='
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>>> base32_encode(b"123456")
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b'GEZDGNBVGY======'
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>>> base32_encode(b"some long complex string")
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b'ONXW2ZJANRXW4ZZAMNXW24DMMV4CA43UOJUW4ZY='
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"""
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binary_data = "".join(bin(ord(d))[2:].zfill(8) for d in data.decode("utf-8"))
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binary_data = binary_data.ljust(5 * ((len(binary_data) // 5) + 1), "0")
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b32_chunks = map("".join, zip(*[iter(binary_data)] * 5))
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b32_result = "".join(B32_CHARSET[int(chunk, 2)] for chunk in b32_chunks)
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return bytes(b32_result.ljust(8 * ((len(b32_result) // 8) + 1), "="), "utf-8")
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def base32_decode(data: bytes) -> bytes:
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"""
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>>> base32_decode(b'JBSWY3DPEBLW64TMMQQQ====')
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b'Hello World!'
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>>> base32_decode(b'GEZDGNBVGY======')
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b'123456'
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>>> base32_decode(b'ONXW2ZJANRXW4ZZAMNXW24DMMV4CA43UOJUW4ZY=')
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b'some long complex string'
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"""
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binary_chunks = "".join(
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bin(B32_CHARSET.index(_d))[2:].zfill(5)
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for _d in data.decode("utf-8").strip("=")
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)
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binary_data = list(map("".join, zip(*[iter(binary_chunks)] * 8)))
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return bytes("".join([chr(int(_d, 2)) for _d in binary_data]), "utf-8")
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if __name__ == "__main__":
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import doctest
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doctest.testmod()
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