Undefined name 'target' in ast_tracer.py

[cclauss]

flake8 testing of https://github.com/IBM/pyflowgraph on Python 3.7.1

$ flake8 . --count --select=E9,F63,F72,F82 --show-source --statistics

./flowgraph/trace/ast_tracer.py:260:25: F821 undefined name 'target'
        elif isinstance(target, ast.List):
                        ^
1     F821 undefined name 'target'
1

E901,E999,F821,F822,F823 are the "showstopper" flake8 issues that can halt the runtime with a SyntaxError, NameError, etc. These 5 are different from most other flake8 issues which are merely "style violations" -- useful for readability but they do not effect runtime safety.

• F821: undefined name name
• F822: undefined name name in __all__
• F823: local variable name referenced before assignment
• E901: SyntaxError or IndentationError
• E999: SyntaxError -- failed to compile a file into an Abstract Syntax Tree