Regular expression filter doesn't work right

[sbuss]

See failing unit test:

FAIL: test_re (tests.test_filters.TestFilter)
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Traceback (most recent call last):
  File "/Users/sbuss/workspace/pypercube/pypercube/tests/test_filters.py", line 64, in test_re
    self.assertEqual("%s" % f, r'.re(name, "\s+([A-Za-z0-9]+)")')
AssertionError: '.re(name, "\\\\s+([A-Za-z0-9]+)")' != '.re(name, "\\s+([A-Za-z0-9]+)")'