'If this test failed, you probably added a new "format unit"
in Python/getargs.c, but neglected to update our poor friend
skipitem() in the same file.  (If so, shame on you!)
With a few exceptions**, this function brute-force tests all
printable ASCII*** characters (32 to 126 inclusive) as format units,
checking to see that PyArg_ParseTupleAndKeywords() return consistent
errors both when the unit is attempted to be used and when it is
skipped.  If the format unit doesn\'t exist, we\'ll get one of two
specific error messages (one for used, one for skipped); if it does
exist we *won\'t* get that error--we\'ll get either no error or some
other error.  If we get the specific "does not exist" error for one
test and not for the other, there\'s a mismatch, and the test fails.
** Some format units have special funny semantics and it would
be difficult to accomodate them here.  Since these are all
well-established and properly skipped in skipitem() we can
get away with not testing them--this test is really intended
to catch *new* format units.
*** Python C source files must be ASCII.  Therefore it\'s impossible
to have non-ASCII format units.'

def test_skipitem(self):

    empty_tuple = ()
    tuple_1 = (0,)
    dict_b = {'b': 1}
    keywords = ['a', 'b']
    for i in range(32, 127):
        c = chr(i)
        if (c in '()e|$'):
            continue
        format = (c + 'i')
        try:
            _testcapi.parse_tuple_and_keywords(tuple_1, dict_b, format.encode('ascii'), keywords)
            when_not_skipped = False
        except TypeError as e:
            s = 'argument    1    must    be    impossible<bad    format    char>,    not    int'
            when_not_skipped = (str(e) == s)
        except RuntimeError as e:
            when_not_skipped = False
        optional_format = ('|' + format)
        try:
            _testcapi.parse_tuple_and_keywords(empty_tuple, dict_b, optional_format.encode('ascii'), keywords)
            when_skipped = False
        except RuntimeError as e:
            s = "impossible<bad    format    char>:    '{}'".format(format)
            when_skipped = (str(e) == s)
        message = "test_skipitem_parity:    detected    mismatch    between    convertsimple    and    skipitem    for    format    unit    '{}'    ({}),    not    skipped    {},    skipped    {}".format(c, i, when_skipped, when_not_skipped)
        self.assertIs(when_skipped, when_not_skipped, message)
