Fix module locals has no builtins

[tomMoral]

Fixes#211

This PR fix the way we detect that a module is importable for local functions.
Note that this not completly fixes the problem in #211 as the issue still appears for dynamic modules eg if you change tests/cloudpickle_test.py from line 419 to

deftest_dynamic_module(self):
mod=types.ModuleType('mod')
code=''' x = 1 def f(y): range(10) return x + y class Foo: def method(self, x): return f(x) '''exec(textwrap.dedent(code), mod.__dict__)
mod2=pickle_depickle(mod, protocol=self.protocol)
self.assertEqual(mod.x, mod2.x)
self.assertEqual(mod.f(5), mod2.f(5))
self.assertEqual(mod.Foo().method(5), mod2.Foo().method(5))
ifplatform.python_implementation() !='PyPy':
# XXX: this fails with excessive recursion on PyPy.mod3=subprocess_pickle_echo(mod, protocol=self.protocol)
self.assertEqual(mod.x, mod3.x)
self.assertEqual(mod.f(5), mod3.f(5))
self.assertEqual(mod.Foo().method(5), mod3.Foo().method(5))
# Test dynamic modules when imported back are singletonsmod1, mod2=pickle_depickle([mod, mod])
self.assertEqual(id(mod1), id(mod2))

then the output of the test is

_______________________________________________________________________________________CloudPickleTest.test_dynamic_module_______________________________________________________________________________________self=<tests.cloudpickle_test.CloudPickleTesttestMethod=test_dynamic_module>deftest_dynamic_module(self):
mod=types.ModuleType('mod')
code=''' x = 1 def f(y): range(10) return x + y class Foo: def method(self, x): return f(x) '''exec(textwrap.dedent(code), mod.__dict__)
mod2=pickle_depickle(mod, protocol=self.protocol)
self.assertEqual(mod.x, mod2.x)
self.assertEqual(mod.f(5), mod2.f(5))
self.assertEqual(mod.Foo().method(5), mod2.Foo().method(5))
ifplatform.python_implementation() !='PyPy':
# XXX: this fails with excessive recursion on PyPy.mod3=subprocess_pickle_echo(mod, protocol=self.protocol)
self.assertEqual(mod.x, mod3.x)
self.assertEqual(mod.f(5), mod3.f(5))
self.assertEqual(mod.Foo().method(5), mod3.Foo().method(5))
# Test dynamic modules when imported back are singletons>mod1, mod2=pickle_depickle([mod, mod])
code='\n x = 1\n def f(y):\n range(10)\n return x + y\n\n class Foo:\n def method(self, x):\n return f(x)\n 'mod=<module'mod'>mod2=<module'mod'>mod3=<module'mod'>self=<tests.cloudpickle_test.CloudPickleTesttestMethod=test_dynamic_module>tests/cloudpickle_test.py:445: __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
tests/cloudpickle_test.py:69: inpickle_depicklereturnpickle.loads(cloudpickle.dumps(obj, protocol=protocol))
cloudpickle/cloudpickle.py:931: indumpscp.dump(obj)
cloudpickle/cloudpickle.py:284: indumpreturnPickler.dump(self, obj)
/usr/lib/python3.4/pickle.py:412: indumpself.save(obj)
/usr/lib/python3.4/pickle.py:479: insavef(self, obj) # Call unbound method with explicit self/usr/lib/python3.4/pickle.py:774: insave_listself._batch_appends(obj)
__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
self=<cloudpickle.cloudpickle.CloudPicklerobjectat0x7f63bc9d3550>, items= [<module'mod'>, <module'mod'>]
def_batch_appends(self, items):
# Helper to batch up APPENDS sequencessave=self.savewrite=self.writeifnotself.bin:
forxinitems:
save(x)
write(APPEND)
returnit=iter(items)
whileTrue:
>tmp=list(islice(it, self._BATCHSIZE))
EKeyError: 'range'it=<list_iteratorobjectat0x7f63bc9d3c50>items= [<module'mod'>, <module'mod'>]
save=<boundmethodCloudPickler.saveof<cloudpickle.cloudpickle.CloudPicklerobjectat0x7f63bc9d3550>>self=<cloudpickle.cloudpickle.CloudPicklerobjectat0x7f63bc9d3550>write=<boundmethod_Framer.writeof<pickle._Framerobjectat0x7f63bc9d3e10>>/usr/lib/python3.4/pickle.py:793: KeyError

But I don't think it is possible to fix that as it probably has to do with internal dealing of python for creating a FunctionType object .

[codecov-io]

Codecov Report

Merging #212 into master will increase coverage by 0.05%.
The diff coverage is 100%.

@@ Coverage Diff @@## master #212 +/- ##
========================================
+ Coverage 84.94% 85% +0.05% 
========================================
Files 1 1 Lines 578 580 +2 Branches 115 114 -1 ========================================
+ Hits 491 493 +2 
Misses 63 63 Partials 24 24

Impacted Files	Coverage Δ
cloudpickle/cloudpickle.py	85% <100%> (+0.05%)	⬆️

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[ogrisel]

LGTM, thanks very much for the fix.