Added replace char challenge.

arrays_strings/replace_char/test_replace_char.py

@@ -0,0 +1,29 @@
+from nose.tools import assert_equal
+
+
+class TestReplace(object):
+    
+    def test_replace_char(self, func):
+        # | are used to satisfy the constraint that
+        # there is enough space in the string to replace
+        # ' ' with '%20'
+        str0 = None
+        str1 = bytearray(' ||')
+        str2 = bytearray(' foo bar ||||||')
+        str3 = bytearray('foo')
+        func(str0, 0)
+        func(str1, 1)
+        func(str2, 9)
+        func(str3, 3)
+        assert_equal(str0, None)
+        assert_equal(str1, '%20')
+        assert_equal(str2, '%20foo%20bar%20')
+        assert_equal(str3, 'foo')
+        print('Success: test_replace_char')
+
+def main():
+    test = TestReplace()
+    test.test_replace_char(encode_spaces)
+    
+if __name__ == '__main__':
+    main()