40 lines
1.0 KiB
Plaintext
40 lines
1.0 KiB
Plaintext
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Trying to access a dictionary key that does not exist will raise a `KeyError`.
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When trying to access or remove a key that may not be there, several solutions are possible:
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* Use the `get()` method instead of a subscription. It will return `None` for a missing key instead of raising a `KeyError`.
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* Use the `setdefault()` method to provide keys that may be missing with a default value.
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* Check that the key is present in the dictionary with the `if key in dict:` construct.
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* Use a `try/except` block and handle the potential `KeyError`.
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* Use a `defaultdict` instead of a regular `dict` object.
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== Noncompliant Code Example
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[source,python]
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----
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def foo():
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my_dict = {'k1': 42}
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...
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value = my_dict['k2'] # Noncompliant
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----
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== Compliant Solution
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[source,python]
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----
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def foo():
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my_dict = {'k1': 42}
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...
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if 'k2' in my_dict:
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value = my_dict['k2']
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----
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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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include::message.adoc[]
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'''
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endif::env-github,rspecator-view[]
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