range: lean and mean

Lib/ctypes/test/test_slicing.py

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

[GvR, 2008/05/03 05:04:35]

Hm... Why can't you assign a range() to a c_int array? Is it because it must be
a list, or because it must be a sequence?  (I'm guessing ctypes ought to accept
any iterable...)

[Benjamin, 2008/05/03 17:18:39]

On 2008/05/03 05:04:35, gvanrossum wrote:
> Hm... Why can't you assign a range() to a c_int array? Is it because it must
be
> a list, or because it must be a sequence?  (I'm guessing ctypes ought to
accept
> any iterable...)

It's because PySequence_GetItem is called on the range. You'd have to ask Thomas
any other questions, though.

         self.failUnlessEqual(a[0:5], list(range(5, 10)))
         self.failUnlessEqual(a[0:5:], list(range(5, 10)))
         self.failUnlessEqual(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.failUnlessEqual(a[32:47], list(range(32, 47)))
@@ skipping 127 matching lines @@
             self.failUnlessEqual(res[:len(s)-1], tmpl)
             self.failUnlessEqual(res[:len(s)-1:], tmpl)
             self.failUnlessEqual(res[len(s)-2:-1:-1], tmpl[::-1])
             self.failUnlessEqual(res[len(s)-2:5:-7], tmpl[:5:-7])
             dll.my_free(res)
 
 ################################################################
 
 if __name__ == "__main__":
     unittest.main()