67 lines
1.6 KiB
Plaintext
67 lines
1.6 KiB
Plaintext
This rule raises an issue when a comparison to `None` is invariant.
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== Why is this an issue?
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Checking if a variable or parameter is `None` should only be done when you expect that it can be `None`. Doing so when the variable is always `None` or never `None` is confusing at best. At worse, there is a bug and the variable is not updated properly.
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This rule raises an issue when expressions `X is None`, `X is not None`, `X == None` or `X != None` are constant, i.e. `X` is always None or never None.
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=== Code examples
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==== Noncompliant code example
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[source,python,diff-id=1,diff-type=noncompliant]
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----
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def foo():
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my_var = None
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if my_var == None: # Noncompliant: always True.
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...
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----
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==== Compliant solution
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[source,python,diff-id=1,diff-type=compliant]
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----
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def foo(my_var):
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if my_var == None:
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...
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----
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:link-with-uscores1: https://docs.python.org/3/reference/datamodel.html#object.__eq__
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== Resources
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=== Documentation
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* Python documentation - https://docs.python.org/3/reference/expressions.html#is-not[Identity comparisons]
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* Python documentation - {link-with-uscores1}[``++__eq__++`` operator]
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ifdef::env-github,rspecator-view[]
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'''
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== Implementation Specification
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(visible only on this page)
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=== Message
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* Remove this identity check; it will always be True/False
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* Remove this == comparison; it will always be True/False
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* Remove this != comparison; it will always be True/False
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=== Highlighting
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the "is", "is not", "==" or "!=" operator
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'''
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== Comments And Links
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(visible only on this page)
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=== is related to: S5914
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endif::env-github,rspecator-view[]
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