The docs also clarify the 'Interesting Example' duplicate-free enum is for
demonstration purposes.

follow_symlinks=False whereas the fchmodat() function is not avaialble.

whereas the fchmodat() function is not avaialble.

functions if a Python exception was raised

handler if a Python exception is set

Modules/python.c:40: warning: ISO C90 forbids mixed declarations and code

Don't call PyErr_NewException() if an exception is set, or type_call() would
fail with an assertion error.

assertion error if they are called with an exception set (PyErr_Occurred()).

As PyEval_EvalFrameEx(), they may clear the current exception and so the caller
looses its exception.

type_call() with an exception set

with an assertion error if they are called with an exception set
(PyErr_Occurred()).

If these functions are called with an exception set, the exception may be
cleared and so the caller looses its exception.

Add also assertions to PyEval_CallObjectWithKeywords() and call_function() to
check if the function succeed with no exception set, or the function failed
with an exception set.

the last call to the step() method of a user function

PyObject_Repr() can removes the current exception. For example, module_repr()
calls PyErr_Clear() if calling loader.module_repr(mod) failed.

small integers (0 or 1 digit)

supports running only selected tests.  Patch by Zachary Ware.

supports running only selected tests.  Patch by Zachary Ware.

Original patch by Zachary Ware.

Original patch by Zachary Ware.

_PyDict_GetItemId() is more efficient: it only builds the Unicode string once.
Identifiers (dictionary keys) are now created at Python initialization, and if
the creation failed, Python does exit with a fatal error.

Before, PyDict_GetItemString() failure was not handled: structseq_new() could
call PyObject_GC_NewVar() with a negative size, and structseq_dealloc() could
also crash.

PyList_Append() (called by PyArena_AddPyObject()) can fail because of a
MemoryError for example.

PyObject_IsSubclass() can fail and raise a new exception!

Type "o" format of Py_BuildValue() is invalid: it must be "O".

It was easy to miss the call to type->tp_init because it was done in a long
conditional expression. Split the long expression in multiple lines to make the
debug step by step easier.