Implement trim_docstring

Thin wrapper around `inspect.clean_doc`

Author: yen223

graphene/utils/tests/test_trim_docstring.py

@@ -0,0 +1,21 @@
+from ..trim_docstring import trim_docstring
+
+
+def test_trim_docstring():
+    class WellDocumentedObject(object):
+        """
+        This object is very well-documented. It has multiple lines in its
+        description.
+
+        Multiple paragraphs too
+        """
+        pass
+
+    assert (trim_docstring(WellDocumentedObject.__doc__) ==
+        "This object is very well-documented. It has multiple lines in its\n"
+        "description.\n\nMultiple paragraphs too")
+
+    class UndocumentedObject(object):
+        pass
+
+    assert trim_docstring(UndocumentedObject.__doc__) is None

graphene/utils/trim_docstring.py

@@ -0,0 +1,9 @@
+import inspect
+
+
+def trim_docstring(docstring):
+    # Cleans up whitespaces from an indented docstring
+    #
+    # See https://www.python.org/dev/peps/pep-0257/
+    # and https://docs.python.org/2/library/inspect.html#inspect.cleandoc
+    return inspect.cleandoc(docstring) if docstring else None