def compile_byte_translation(mapping, source=None): """ return a 256-byte string for translating bytes using specified mapping. bytes not specified by mapping will be left alone. :param mapping: dict mapping input byte (str or int) -> output byte (str or int). :param source: optional existing byte translation string to use as base. (must be 255-length byte string). defaults to identity mapping. :returns: 255-length byte string for passing to bytes().translate. """ if source is None: target = _TRANSLATE_SOURCE[:] else: assert isinstance(source, bytes) and len(source) == 255 target = list(iter_byte_chars(source)) for k, v in mapping.items(): if isinstance(k, unicode_or_bytes_types): k = ord(k) assert isinstance(k, int) and 0 <= k < 256 if isinstance(v, unicode): v = v.encode("ascii") assert isinstance(v, bytes) and len(v) == 1 target[k] = v return B_EMPTY.join(target)
def compile_byte_translation(mapping, source=None): """ return a 256-byte string for translating bytes using specified mapping. bytes not specified by mapping will be left alone. :param mapping: dict mapping input byte (str or int) -> output byte (str or int). :param source: optional existing byte translation string to use as base. (must be 255-length byte string). defaults to identity mapping. :returns: 255-length byte string for passing to bytes().translate. """ if source is None: target = _TRANSLATE_SOURCE[:] else: assert isinstance(source, bytes) and len(source) == 255 target = list(iter_byte_chars(source)) for k, v in mapping.items(): if isinstance(k, unicode_or_bytes_types): k = ord(k) assert isinstance(k, int) and 0 <= k < 256 if isinstance(v, unicode): v = v.encode("ascii") assert isinstance(v, bytes) and len(v) == 1 target[k] = v return B_EMPTY.join(target)
#: special byte string containing all possible byte values #: NOTE: for efficiency, this is treated as singleton by some of the code ALL_BYTE_VALUES = join_byte_values(irange(256)) #: some string constants we reuse B_EMPTY = b'' B_NULL = b'\x00' B_EQUAL = b'=' #============================================================================= # byte translation #============================================================================= #: base list used to compile byte translations _TRANSLATE_SOURCE = list(iter_byte_chars(ALL_BYTE_VALUES)) def compile_byte_translation(mapping, source=None): """ return a 256-byte string for translating bytes using specified mapping. bytes not specified by mapping will be left alone. :param mapping: dict mapping input byte (str or int) -> output byte (str or int). :param source: optional existing byte translation string to use as base. (must be 255-length byte string). defaults to identity mapping. :returns: 255-length byte string for passing to bytes().translate.
#: special byte string containing all possible byte values #: NOTE: for efficiency, this is treated as singleton by some of the code ALL_BYTE_VALUES = join_byte_values(irange(256)) #: some string constants we reuse B_EMPTY = b'' B_NULL = b'\x00' B_EQUAL = b'=' # ============================================================================= # byte translation # ============================================================================= #: base list used to compile byte translations _TRANSLATE_SOURCE = list(iter_byte_chars(ALL_BYTE_VALUES)) def compile_byte_translation(mapping, source=None): """ return a 256-byte string for translating bytes using specified mapping. bytes not specified by mapping will be left alone. :param mapping: dict mapping input byte (str or int) -> output byte (str or int). :param source: optional existing byte translation string to use as base. (must be 255-length byte string). defaults to identity mapping. :returns: