* Check intersection of two sets explicitly
Comparing ``len(a) > ``len(a - b)`` is essentially looking for an
intersection between the two sets. If set ``b`` does not intersect ``a``
then ``len(a - b)`` will be equal to ``len(a)``. This logic is more
clearly expressed as ``a & b``.
* Change while/pop to a for-loop
Copying the list, then repeatedly popping the first element was
unnecessarily slow. I also cleaned up a couple other inefficiencies.
There's no need to unpack a tuple, then re-pack and append it. The list
can be created with the first element instead of empty. Secondly, the
``endswith`` method returns a bool, so there's no need for an if-
statement to set ``encoding`` to True or False.
* Use set.intersection to check for intersections
``a.intersection(b)`` method is more clear of purpose than ``not
a.isdisjoint(b)`` and avoids an unnecessary set construction that ``a &
set(b)`` performs.
* Use not isdisjoint instead of intersection
While it reads slightly worse, the isdisjoint method will stop when it
finds a counterexample and returns a bool, rather than looping over the
entire iterable and constructing a new set.
Add _PyRuntimeState.preinitializing field: set to 1 while
Py_PreInitialize() is running.
_PyRuntimeState: rename also pre_initialized field to preinitialized.
Even when the helper is not started yet.
This behavior follows conventional generator one.
There is no reason for `async_generator_athrow` to handle `gen.throw()` differently.
https://bugs.python.org/issue38013
In the format string for assert_called the evaluation order is incorrect and hence for mock's without name, 'None' is printed whereas it should be 'mock' like for other messages. The error message is ("Expected '%s' to have been called." % self._mock_name or 'mock').
When using multiprocesss (-jN), the main process now uses a timeout
of 60 seconds instead of the double of the --timeout value. The
buildbot server stops a job which does not produce any output in 1200
seconds.
This PR replaces the old note mentioning that `typing` is a provisional module with a new one mentioning types are not enforced at runtime. I am not sure if there was any official announcement about making `typing` non-provisional, but _de-facto_ no new features were added during Python 3.7, and no backwards incompatible changes were made except for few small things that were considered bugs.
Typically, the second positional argument for ``seek()`` is *whence*. That is the POSIX standard name (http://man7.org/linux/man-pages/man3/lseek.3p.html) and the name listed in the documentation for ``io`` module (https://docs.python.org/3/library/io.html#io.IOBase.seek).
The tutorial for IO is the only location where the second positional argument for ``seek()`` is referred to as *from_what*. I suspect this was created at an early point in Python's history, and was never updated (as this section predates the GitHub repository):
```
$ git grep "from_what"
Doc/tutorial/inputoutput.rst:To change the file object's position, use ``f.seek(offset, from_what)``. The position is computed
Doc/tutorial/inputoutput.rst:the *from_what* argument. A *from_what* value of 0 measures from the beginning
Doc/tutorial/inputoutput.rst:the reference point. *from_what* can be omitted and defaults to 0, using the
```
For consistency, I am suggesting that the tutorial be updated to use the same argument name as the IO documentation and POSIX standard for ``seek()``, particularly since this is the only location where *from_what* is being used.
Note: In the POSIX standard, *whence* is technically the third positional argument, but the first argument *fildes* (file descriptor) is implicit in Python.
https://bugs.python.org/issue37635