test_slicing.py | Explore in Territory

import unittest
from ctypes import (CDLL, POINTER, sizeof,
                    c_byte, c_short, c_int, c_long, c_char, c_wchar, c_char_p)
from test.support import import_helper
_ctypes_test = import_helper.import_module("_ctypes_test")


class SlicesTestCase(unittest.TestCase):
    def test_getslice_cint(self):
        a = (c_int * 100)(*range(1100, 1200))
        b = list(range(1100, 1200))
        self.assertEqual(a[0:2], b[0:2])
        self.assertEqual(a[0:2:], b[0:2:])
        self.assertEqual(len(a), len(b))
        self.assertEqual(a[5:7], b[5:7])
        self.assertEqual(a[5:7:], b[5:7:])
        self.assertEqual(a[-1], b[-1])
        self.assertEqual(a[:], b[:])
        self.assertEqual(a[::], b[::])
        self.assertEqual(a[10::-1], b[10::-1])
        self.assertEqual(a[30:20:-1], b[30:20:-1])
        self.assertEqual(a[:12:6], b[:12:6])
        self.assertEqual(a[2:6:4], b[2:6:4])

        a[0:5] = range(5, 10)
        self.assertEqual(a[0:5], list(range(5, 10)))
        self.assertEqual(a[0:5:], list(range(5, 10)))
        self.assertEqual(a[4::-1], list(range(9, 4, -1)))

    def test_setslice_cint(self):
        a = (c_int * 100)(*range(1100, 1200))
        b = list(range(1100, 1200))

        a[32:47] = list(range(32, 47))
        self.assertEqual(a[32:47], list(range(32, 47)))
        a[32:47] = range(132, 147)
        self.assertEqual(a[32:47:], list(range(132, 147)))
        a[46:31:-1] = range(232, 247)
        self.assertEqual(a[32:47:1], list(range(246, 231, -1)))

        a[32:47] = range(1132, 1147)
        self.assertEqual(a[:], b)
        a[32:47:7] = range(3)
        b[32:47:7] = range(3)
        self.assertEqual(a[:], b)
        a[33::-3] = range(12)
        b[33::-3] = range(12)
        self.assertEqual(a[:], b)

        # TypeError: int expected instead of str instance
        with self.assertRaises(TypeError):
            a[:5] = "abcde"

        # TypeError: int expected instead of str instance
        with self.assertRaises(TypeError):
            a[:5] =  ["a", "b", "c", "d", "e"]

        # TypeError: int expected instead of float instance
        with self.assertRaises(TypeError):
            a[:5] = [1, 2, 3, 4, 3.14]

        # ValueError: Can only assign sequence of same size
        with self.assertRaises(ValueError):
            a[:5] = range(32)

    def test_char_ptr(self):
        s = b"abcdefghijklmnopqrstuvwxyz"

        dll = CDLL(_ctypes_test.__file__)
        dll.my_strdup.restype = POINTER(c_char)
        dll.my_free.restype = None
        res = dll.my_strdup(s)
        self.assertEqual(res[:len(s)], s)
        self.assertEqual(res[:3], s[:3])
        self.assertEqual(res[:len(s):], s)
        self.assertEqual(res[len(s)-1:-1:-1], s[::-1])
        self.assertEqual(res[len(s)-1:5:-7], s[:5:-7])
        self.assertEqual(res[0:-1:-1], s[0::-1])

        # get items
        with self.assertRaises(ValueError):
            res[:]
        with self.assertRaises(ValueError):
            res[0:]
        with self.assertRaises(ValueError):
            res[:5:-1]
        with self.assertRaises(ValueError):
            res[-5:]

        # set items
        with self.assertRaises(TypeError):
            res[:5] = "abcde"

        dll.my_free(res)

        dll.my_strdup.restype = POINTER(c_byte)
        res = dll.my_strdup(s)
        self.assertEqual(res[:len(s)], list(range(ord("a"), ord("z")+1)))
        self.assertEqual(res[:len(s):], list(range(ord("a"), ord("z")+1)))
        dll.my_free(res)

    def test_char_ptr_with_free(self):
        dll = CDLL(_ctypes_test.__file__)
        s = b"abcdefghijklmnopqrstuvwxyz"

        class allocated_c_char_p(c_char_p):
            pass

        dll.my_free.restype = None
        def errcheck(result, func, args):
            retval = result.value
            dll.my_free(result)
            return retval

        dll.my_strdup.restype = allocated_c_char_p
        dll.my_strdup.errcheck = errcheck
        try:
            res = dll.my_strdup(s)
            self.assertEqual(res, s)
        finally:
            del dll.my_strdup.errcheck


    def test_char_array(self):
        s = b"abcdefghijklmnopqrstuvwxyz\0"

        p = (c_char * 27)(*s)
        self.assertEqual(p[:], s)
        self.assertEqual(p[::], s)
        self.assertEqual(p[::-1], s[::-1])
        self.assertEqual(p[5::-2], s[5::-2])
        self.assertEqual(p[2:5:-3], s[2:5:-3])


    def test_wchar_ptr(self):
        s = "abcdefghijklmnopqrstuvwxyz\0"

        dll = CDLL(_ctypes_test.__file__)
        dll.my_wcsdup.restype = POINTER(c_wchar)
        dll.my_wcsdup.argtypes = POINTER(c_wchar),
        dll.my_free.restype = None
        res = dll.my_wcsdup(s[:-1])
        self.assertEqual(res[:len(s)], s)
        self.assertEqual(res[:len(s):], s)
        self.assertEqual(res[len(s)-1:-1:-1], s[::-1])
        self.assertEqual(res[len(s)-1:5:-7], s[:5:-7])

        with self.assertRaises(TypeError):
            res[:5] = "abcde"
        dll.my_free(res)

        if sizeof(c_wchar) == sizeof(c_short):
            dll.my_wcsdup.restype = POINTER(c_short)
        elif sizeof(c_wchar) == sizeof(c_int):
            dll.my_wcsdup.restype = POINTER(c_int)
        elif sizeof(c_wchar) == sizeof(c_long):
            dll.my_wcsdup.restype = POINTER(c_long)
        else:
            self.skipTest('Pointers to c_wchar are not supported')
        res = dll.my_wcsdup(s[:-1])
        tmpl = list(range(ord("a"), ord("z")+1))
        self.assertEqual(res[:len(s)-1], tmpl)
        self.assertEqual(res[:len(s)-1:], tmpl)
        self.assertEqual(res[len(s)-2:-1:-1], tmpl[::-1])
        self.assertEqual(res[len(s)-2:5:-7], tmpl[:5:-7])
        dll.my_free(res)


if __name__ == "__main__":
    unittest.main()
cpython/Lib/test/test_ctypes/test_slicing.py
