42 lines
1.4 KiB
Python
42 lines
1.4 KiB
Python
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"""Functions for encoding and decoding strings."""
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from __future__ import (absolute_import, division, print_function)
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__metaclass__ = type
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from . import types as t
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ENCODING = 'utf-8'
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Text = type(u'')
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def to_optional_bytes(value, errors='strict'): # type: (t.Optional[t.AnyStr], str) -> t.Optional[bytes]
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"""Return the given value as bytes encoded using UTF-8 if not already bytes, or None if the value is None."""
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return None if value is None else to_bytes(value, errors)
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def to_optional_text(value, errors='strict'): # type: (t.Optional[t.AnyStr], str) -> t.Optional[t.Text]
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"""Return the given value as text decoded using UTF-8 if not already text, or None if the value is None."""
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return None if value is None else to_text(value, errors)
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def to_bytes(value, errors='strict'): # type: (t.AnyStr, str) -> bytes
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"""Return the given value as bytes encoded using UTF-8 if not already bytes."""
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if isinstance(value, bytes):
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return value
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if isinstance(value, Text):
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return value.encode(ENCODING, errors)
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raise Exception('value is not bytes or text: %s' % type(value))
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def to_text(value, errors='strict'): # type: (t.AnyStr, str) -> t.Text
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"""Return the given value as text decoded using UTF-8 if not already text."""
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if isinstance(value, bytes):
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return value.decode(ENCODING, errors)
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if isinstance(value, Text):
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return value
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raise Exception('value is not bytes or text: %s' % type(value))
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