Merge pull request #821 from martindurant/function_serialize

Raise when trying to store a dynamic function

intake/readers/tests/test_errors.py

@@ -0,0 +1,18 @@
+import pytest
+
+import intake
+
+
+def test_func_ser():
+    class A:
+        def get(self):
+            def inner():
+                return self.x
+
+            return inner
+
+    func = A().get()
+    reader = intake.readers.convert.GenericFunc(data=func)
+    cat = intake.Catalog()
+    with pytest.raises(RuntimeError):
+        cat.add_entry(reader)

intake/readers/utils.py

@@ -120,7 +120,10 @@ def find_funcs(val, tokens={}):
     if isinstance(val, Tokenizable):
         return val.to_dict()
     elif callable(val):
-        return "{func(%s)}" % f"{val.__module__}:{val.__name__}"
+        name = "{func(%s)}" % f"{val.__module__}:{val.__name__}"
+        if "<locals>" in name or "__main__" in name or getattr(val, "__closure__", False):
+            raise RuntimeError("Cannot store dynamically defined function: %s", val)
+        return name
     elif val is None or isinstance(val, (numbers.Number, BaseData, BaseReader)):
         return val
     else: