Update of /cvsroot/python/python/dist/src/Lib/test In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv21408/Lib/test Modified Files: string_tests.py Log Message: * Beef-up testing of str.__contains__() and str.find(). * Speed-up "x in y" where x has more than one character. The existing code made excessive calls to the expensive memcmp() function. The new code uses memchr() to rapidly find a start point for memcmp(). In addition to knowing that the first character is a match, the new code also checks that the last character is a match. This significantly reduces the incidence of false starts (saving memcmp() calls and making quadratic behavior less likely). Improves the timings on: python -m timeit -r7 -s"x='a'*1000" "'ab' in x" python -m timeit -r7 -s"x='a'*1000" "'bc' in x" Once this code has proven itself, then string_find_internal() should refer to it rather than running its own version. Also, something similar may apply to unicode objects. Index: string_tests.py =================================================================== RCS file: /cvsroot/python/python/dist/src/Lib/test/string_tests.py,v retrieving revision 1.42 retrieving revision 1.43 diff -u -d -r1.42 -r1.43 --- string_tests.py 26 Oct 2004 01:52:36 -0000 1.42 +++ string_tests.py 20 Feb 2005 04:07:08 -0000 1.43 @@ -122,6 +122,30 @@ self.checkraises(TypeError, 'hello', 'find') self.checkraises(TypeError, 'hello', 'find', 42) + # For a variety of combinations, + # verify that str.find() matches __contains__ + # and that the found substring is really at that location + charset = ['', 'a', 'b', 'c'] + digits = 5 + base = len(charset) + teststrings = set() + for i in xrange(base ** digits): + entry = [] + for j in xrange(digits): + i, m = divmod(i, base) + entry.append(charset[m]) + teststrings.add(''.join(entry)) + for i in teststrings: + i = self.fixtype(i) + for j in teststrings: + loc = i.find(j) + r1 = (loc != -1) + r2 = j in i + if r1 != r2: + self.assertEqual(r1, r2) + if loc != -1: + self.assertEqual(i[loc:loc+len(j)], j) + def test_rfind(self): self.checkequal(9, 'abcdefghiabc', 'rfind', 'abc') self.checkequal(12, 'abcdefghiabc', 'rfind', '')