fix the bug

python/cudf/cudf/tests/test_udf_masked_ops.py

@@ -593,3 +593,22 @@ def func(row, c, k):
         return y
 
     run_masked_udf_test(func, data, args=(1, 2), check_dtype=False)
+
+
+def test_masked_udf_caching():
+    # Make sure similar functions that differ
+    # by simple things like constants actually
+    # recompile
+
+    data = cudf.Series([1, 2, 3])
+    expect = data ** 2
+    got = data.applymap(lambda x: x ** 2)
+
+    assert_eq(expect, got, check_dtype=False)
+
+    # update the constant value being used and make sure
+    # it does not result in a cache hit
+
+    expect = data ** 3
+    got = data.applymap(lambda x: x ** 3)
+    assert_eq(expect, got, check_dtype=False)

python/cudf/cudf/utils/cudautils.py

@@ -216,12 +216,14 @@ def make_cache_key(udf, sig):
     recompiling the same function for the same set of types
     """
     codebytes = udf.__code__.co_code
+    constants = udf.__code__.co_consts
     if udf.__closure__ is not None:
         cvars = tuple([x.cell_contents for x in udf.__closure__])
         cvarbytes = dumps(cvars)
     else:
         cvarbytes = b""
-    return codebytes, cvarbytes, sig
+
+    return constants, codebytes, cvarbytes, sig
 
 
 def compile_udf(udf, type_signature):