Set __module__ on curried objects. This can fix pickling global curried objects.

Should fix dask/distributed#725

This was an oversight that should have been handled in #326.  We only tested
objects defined in `toolz.functoolz`, so pickling accidentally worked, because
they were in the same module as `curry`.

Author: eriknw

toolz/functoolz.py

@@ -200,6 +200,7 @@ def __init__(self, *args, **kwargs):
 
         self.__doc__ = getattr(func, '__doc__', None)
         self.__name__ = getattr(func, '__name__', '<curry>')
+        self.__module__ = getattr(func, '__module__', None)
         self._sigspec = None
         self._has_unknown_args = None
 

toolz/tests/test_functoolz.py

@@ -289,12 +289,19 @@ def foo(a, b, c=1):
     f = curry(foo, 1, c=2)
     f.__name__ = 'newname'
     f.__doc__ = 'newdoc'
+    f.__module__ = 'newmodule'
     assert f.__name__ == 'newname'
     assert f.__doc__ == 'newdoc'
+    assert f.__module__ == 'newmodule'
     if hasattr(f, 'func_name'):
         assert f.__name__ == f.func_name
 
 
+def test_curry_module():
+    from toolz.curried.exceptions import merge
+    assert merge.__module__ == 'toolz.curried.exceptions'
+
+
 def test_curry_comparable():
     def foo(a, b, c=1):
         return a + b + c

toolz/tests/test_serialization.py

@@ -1,5 +1,6 @@
 from toolz import *
 import toolz
+import toolz.curried.exceptions
 import pickle
 
 
@@ -55,3 +56,9 @@ def test_flip():
     g1 = flip(f)(1)
     g2 = pickle.loads(pickle.dumps(g1))
     assert g1(2) == g2(2) == f(2, 1)
+
+
+def test_curried_exceptions():
+    # This tests a global curried object that isn't defined in toolz.functoolz
+    merge = pickle.loads(pickle.dumps(toolz.curried.exceptions.merge))
+    assert merge is toolz.curried.exceptions.merge