Issue #19619: Blacklist non-text codecs in method API
str.encode, bytes.decode and bytearray.decode now use an
internal API to throw LookupError for known non-text encodings,
rather than attempting the encoding or decoding operation and
then throwing a TypeError for an unexpected output type.
The latter mechanism remains in place for third party non-text
encodings.
diff --git a/Lib/codecs.py b/Lib/codecs.py
index 6a6eb90..2e2e755 100644
--- a/Lib/codecs.py
+++ b/Lib/codecs.py
@@ -73,9 +73,19 @@
### Codec base classes (defining the API)
class CodecInfo(tuple):
+ """Codec details when looking up the codec registry"""
+
+ # Private API to allow Python 3.4 to blacklist the known non-Unicode
+ # codecs in the standard library. A more general mechanism to
+ # reliably distinguish test encodings from other codecs will hopefully
+ # be defined for Python 3.5
+ #
+ # See http://bugs.python.org/issue19619
+ _is_text_encoding = True # Assume codecs are text encodings by default
def __new__(cls, encode, decode, streamreader=None, streamwriter=None,
- incrementalencoder=None, incrementaldecoder=None, name=None):
+ incrementalencoder=None, incrementaldecoder=None, name=None,
+ *, _is_text_encoding=None):
self = tuple.__new__(cls, (encode, decode, streamreader, streamwriter))
self.name = name
self.encode = encode
@@ -84,6 +94,8 @@
self.incrementaldecoder = incrementaldecoder
self.streamwriter = streamwriter
self.streamreader = streamreader
+ if _is_text_encoding is not None:
+ self._is_text_encoding = _is_text_encoding
return self
def __repr__(self):