65 lines
1.7 KiB
Plaintext
65 lines
1.7 KiB
Plaintext
This rule raises an issue when the ``++__init__++`` method of a class contains a `return` or a `yield` statement.
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== Why is this an issue?
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By contract, every Python function returns something, even if it is the ``++None++`` value, which can be returned implicitly by omitting the ``++return++`` statement, or explicitly.
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The ``++__init__++`` method is required to return ``++None++``. A ``++TypeError++`` will be raised if the ``++__init__++`` method either yields or returns any expression other than ``++None++``. While explicitly returning an expression that evaluates to ``++None++`` will not raise an error, it is considered bad practice.
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To fix this issue, make sure that the ``++__init__++`` method does not contain any return statement.
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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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class MyClass(object):
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def __init__(self):
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self.message = 'Hello'
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return self # Noncompliant: a TypeError will be raised
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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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class MyClass(object):
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def __init__(self):
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self.message = 'Hello'
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----
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== Resources
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=== Documentation
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* https://docs.python.org/3/reference/datamodel.html#object.++__init__++[The ``++__init__++`` method]
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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 yield statement.
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* Remove this return value.
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'''
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== Comments And Links
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(visible only on this page)
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=== relates to: S5654
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=== on 18 Mar 2015, 17:55:42 Ann Campbell wrote:
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-E0100: __init__ method is a generator
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-E0101: Explicit return in __init__
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endif::env-github,rspecator-view[]
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