pylint 3.3.6 reports
test.py:1:0: C0114: Missing module docstring (missing-module-docstring)
test.py:4:4: C0103: Constant name "x" doesn't conform to UPPER_CASE naming style (invalid-name)
test.py:6:6: E0606: Possibly using variable 'x' before assignment (possibly-used-before-assignment)
seems enough.