Some applications (e.g. traditional Unix diff, version control
systems) neither know nor care about the encodings of the files they
are comparing. They are textual, but to the diff utility they are just
bytes. This worked fine under Python 2, because all of the hardcoded
strings in difflib.py are ASCII, so could safely be combined with
old-style u'' strings. But it stopped working in 3.x.
The solution is to use surrogate escapes for a lossless
bytes->str->bytes roundtrip. That means {unified,context}_diff() can
continue to just handle strings without worrying about bytes. Callers
who have to deal with bytes will need to change to using diff_bytes().
Use case: Mercurial's test runner uses difflib to compare current hg
output with known good output. But Mercurial's output is just bytes,
since it can contain:
* file contents (arbitrary unknown encoding)
* filenames (arbitrary unknown encoding)
* usernames and commit messages (usually UTF-8, but not guaranteed
because old versions of Mercurial did not enforce it)
* user messages (locale encoding)
Since the output of any given hg command can include text in multiple
encodings, it is hopeless to try to treat it as decodable Unicode
text. It's just bytes, all the way down.
This is an elaboration of a patch by Terry Reedy.
This fix is a superset of the functionality introduced by the issue #19494
enhancement, and supersedes that fix. Instead of a new handler, we have a new
password manager that tracks whether we should send the auth for a given uri.
This allows us to say "always send", satisfying #19494, or track that we've
succeeded in auth and send the creds right away on every *subsequent* request.
The support for using the password manager is added to AbstractBasicAuth,
which means the proxy handler also now can handle prior auth if passed
the new password manager.
Patch by Akshit Khurana, docs mostly by me.
The concept of .pyo files no longer exists. Now .pyc files have an
optional `opt-` tag which specifies if any extra optimizations beyond
the peepholer were applied.
GzipFile, BZ2File or LZMAFile. This defeats denial of service attacks
using compressed bombs (i.e. compressed payloads which decompress to a huge
size).
Patch by Martin Panter and Nikolaus Rath.
