75 lines
1.8 KiB
Python
75 lines
1.8 KiB
Python
# String encodings and numeric representations
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import binascii
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import re
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from typing import (
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Any,
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AnyStr,
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)
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from ..typing import (
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HexStr,
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)
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from .types import (
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is_string,
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is_text,
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)
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_HEX_REGEXP = re.compile("(0[xX])?[0-9a-fA-F]*")
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def decode_hex(value: str) -> bytes:
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if not is_text(value):
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raise TypeError("Value must be an instance of str")
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non_prefixed = remove_0x_prefix(HexStr(value))
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# unhexlify will only accept bytes type someday
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ascii_hex = non_prefixed.encode("ascii")
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return binascii.unhexlify(ascii_hex)
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def encode_hex(value: AnyStr) -> HexStr:
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if not is_string(value):
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raise TypeError("Value must be an instance of str or unicode")
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elif isinstance(value, (bytes, bytearray)):
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ascii_bytes = value
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else:
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ascii_bytes = value.encode("ascii")
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binary_hex = binascii.hexlify(ascii_bytes)
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return add_0x_prefix(HexStr(binary_hex.decode("ascii")))
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def is_0x_prefixed(value: str) -> bool:
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if not is_text(value):
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raise TypeError(
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f"is_0x_prefixed requires text typed arguments. Got: {repr(value)}"
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)
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return value.startswith(("0x", "0X"))
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def remove_0x_prefix(value: HexStr) -> HexStr:
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if is_0x_prefixed(value):
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return HexStr(value[2:])
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return value
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def add_0x_prefix(value: HexStr) -> HexStr:
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if is_0x_prefixed(value):
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return value
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return HexStr("0x" + value)
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def is_hexstr(value: Any) -> bool:
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if not is_text(value) or not value:
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return False
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return _HEX_REGEXP.fullmatch(value) is not None
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def is_hex(value: Any) -> bool:
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if not is_text(value):
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raise TypeError(f"is_hex requires text typed arguments. Got: {repr(value)}")
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if not value:
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return False
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return _HEX_REGEXP.fullmatch(value) is not None
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