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dhondtadhondta
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Added new codec: manchester
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‎README.md‎

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@@ -26,6 +26,7 @@ This library extends the native `codecs` library and provides some new encodings
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`gray` | text <-> gray encoded text | aka reflected binary code
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`html` | text <-> HTML entities | implements entities according to [this reference](https://dev.w3.org/html5/html-author/charref)
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`leetspeak` | text <-> leetspeak encoded text | based on minimalistic elite speaking rules
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`manchester` | text <-> manchester encoded text | XORes each bit of the input with `01`
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`markdown` | markdown --> HTML | unidirectional
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`morse` | text <-> morse encoded text | uses whitespace as a separator
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`navajo` | text <-> Navajo | only handles letters (not full words from the Navajo dictionary)
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:---: | :---: | ---
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`baudot-spaced` | text <-> Baudot code groups of bits | groups of 5 bits are whitespace-separated
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`baudot-tape` | text <-> Baudot code tape | outputs a string that looks like a perforated tape
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`manchester-inverted` | text <-> manchester encoded text | XORes each bit of the input with `10`
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`octal-spaced` | text <-> octal digits (whitespace-separated) | dummy octal conversion
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`ordinal-spaced` | text <-> ordinal digits (whitespace-separated) | dummy character ordinals conversion
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`southpark-icase` | text <-> Kenny's language | same as `southpark` but case insensitive

‎codext/binary/__init__.py‎

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from .baudot import *
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from .excess3 import *
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from .gray import *
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from .manchester import *
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‎codext/binary/manchester.py‎

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# -*- coding: UTF-8 -*-
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"""Manchester Codec - Manchester content encoding.
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This codec:
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- en/decodes strings from str to str
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- en/decodes strings from bytes to bytes
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- decodes file content to str (read)
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- encodes file content from str to bytes (write)
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"""
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from ..__common__ import *
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__examples1__ = {'enc(manchester)': {'This is a test!': "fei\x95i\x96jZYUi\x96jZYUiVYUjeifjZjeYV"}}
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__examples2__ = {
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'enc(manchester-inverted|ethernet|ieee802.4)': {
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'This is a test!': "\x99\x9a\x96j\x96i\x95\xa5\xa6\xaa\x96i\x95\xa5\xa6\xaa\x96\xa9\xa6\xaa\x95\x9a\x96\x99"
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"\x95\xa5\x95\x9a\xa6\xa9",
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},
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}
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def manchester_encode(clock):
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def encode(text, errors="strict"):
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r = ""
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for c in text:
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bin_c = bin(ord(c))[2:].zfill(8)
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for i in range(0, 8, 4):
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r += chr(int("".join(2*bit for bit in bin_c[i:i+4]), 2) ^ clock)
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return r, len(b(text))
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return encode
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def manchester_decode(clock):
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def decode(text, errors="strict"):
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r, bits = "", ""
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for c in text:
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bin_c = bin(ord(c) ^ clock)[2:].zfill(8)
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bits += "".join(bin_c[i] for i in range(0, len(bin_c), 2))
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if len(bits) == 8:
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r += chr(int(bits, 2))
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bits = ""
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return r, len(b(text))
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return decode
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add("manchester", manchester_encode(0x55), manchester_decode(0x55), examples=__examples1__)
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add("manchester-inverted", manchester_encode(0xaa), manchester_decode(0xaa), examples=__examples2__,
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pattern=r"^(?:manchester-inverted|ethernet|ieee802\.4)$")
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‎docs/binary.md‎

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-----
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### Excess-3 Code
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### Excess-3
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Also called *Stibitz code*, it converts letters to ordinals, left-pads with zeros and then applies Excess-3 (Stibitz) code to get groups of 4 bits that are finally reassembled into bytes.
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-----
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### Gray Code
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### Gray
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Also called *reflected binary code*, it implements the Gray code applied to characters while converted to bytes.
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'THIS IS A TEST'
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```
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-----
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### Manchester
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This codec XORes each group of 4 bits of the input text with a 1-byte clock signal, e.g. `0x55` giving in binary `01010101`.
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**Codec** | **Conversions** | **Aliases** | **Comment**
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:---: | :---: | --- | ---
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`manchester` | text <-> manchester encoded text | | clock signal is `0x55` (`01010101`)
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`manchester-inverted` | text <-> manchester encoded text | `ethernet`, `ieee802.4` | clock signal is `0xaa` (`10101010`)
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```python
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>>> codext.encode("This is a test!", "manchester")
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'fei\x95i\x96jZYUi\x96jZYUiVYUjeifjZjeYV'
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>>> codext.decode("fei\x95i\x96jZYUi\x96jZYUiVYUjeifjZjeYV", "manchester")
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'This is a test!'
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>>> codext.encode("This is a test!", "manchester-inverted")
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'\x99\x9a\x96j\x96i\x95¥¦ª\x96i\x95¥¦ª\x96©¦ª\x95\x9a\x96\x99\x95¥\x95\x9a¦©'
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>>> codext.decode("\x99\x9a\x96j\x96i\x95¥¦ª\x96i\x95¥¦ª\x96©¦ª\x95\x9a\x96\x99\x95¥\x95\x9a¦©", "ethernet")
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'This is a test!'
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```
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