It's very unlikely, though possible that source is not a string.  Verify that PyString_AsString() returns a valid pointer.  (The problem can arise when zlib.decompress doesn't return a string.)
It's very unlikely, though possible that source is not a string.  Verify
that PyString_AsString() returns a valid pointer.  (The problem can
arise when zlib.decompress doesn't return a string.)

Klocwork 346

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator