clock_gettime(CLOCK_REALTIME) has a better resolution than gettimeofday().
time.time() falls back on gettimeofday() (and then on other functions) on
error.

And call mach_absolute_time() after mach_timebase_info().

These functions simplify the usage of static constant Unicode strings.
Generalize the usage of _Py_Identifier in ceval.c and typeobject.c.

floattime() must not raise an error if the current time is 1970.1.1 at 00:00.

  without mainloop.

  Thanks to Roger Serwy for patch.

samples and a reference. Also fix the other nits mentioned in the issue.

This also partially addresses issue #14006.

in sys_update_path().

unittest.mock: a mock created by patch with a spec as the list argument will be callable if __call__ is in the spec