"""Verify whitespace handling in str.split and .strip methods."""

import string
import unicodedata as ud

whitespace = frozenset(string.whitespace)


def iswhitespace(c):
    # According to the documentation, this is the definitive
    # test for whitespaceness.
    return ud.category(c) == 'Zs' or ud.bidirectional(c) in ('WS', 'B', 'S')

def fmt(c):
    """Format character c as U+XXXX."""
    return 'U+%04X {%s}' % (ord(c), ud.name(c, ''))

def every_unicode():
    """Iterate over the entire Unicode character set."""
    i = 0
    try:
        while True:
            yield chr(i)
            i += 1
    except ValueError:
        assert i == 0x110000


# ===========================================================================
# compare_* functions return None on success and an error message on failure.

def compare_whitespace_tests(c):
    if c.isspace():
        if not iswhitespace(c):
            return 'str.isspace() returns True on non-whitespace character'
    else:
        if iswhitespace(c):
            return 'str.isspace() returns False on whitespace character'

def compare_string_const(c):
    if c in whitespace:
        if not c.isspace():
            return "non-whitespace character in string.whitespace"
    else:
        if c.isspace():
            return "whitespace character missing from string.whitespace"

def compare_split(c):
    s = 'a' + c + 'b'
    if c.isspace():
        if s.split() != ['a', 'b']:
            return "string.split() fails to split on whitespace"
    else:
        if s.split() == ['a', 'b']:
            return "string.split() splits on non-whitespace"

def compare_strip(c):
    s = c + 'a' + c
    if c.isspace():
        if s.strip() != 'a':
            return "string.strip() fails to strip whitespace"
    else:
        if s.strip() == 'a':
            return "string.strip() strips non-whitespace"

# ===========================================================================


def main():
    for c in every_unicode():
        for test in (compare_whitespace_tests,
                     compare_string_const,
                     compare_split,
                     compare_strip
                     ):
            err = test(c)
            if err is not None:
                print(fmt(c), err)



if __name__ == '__main__':
    main()