This rule raises an issue when the __init__ method of a class contains a return or a yield statement.

Why is this an issue?

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.

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.

To fix this issue, make sure that the __init__ method does not contain any return statement.

Code examples

Noncompliant code example

class MyClass(object):
    def __init__(self):
        self.message = 'Hello'
        return self  # Noncompliant: a TypeError will be raised

Compliant solution

class MyClass(object):
    def __init__(self):
        self.message = 'Hello'

Resources

Documentation

• The __init__ method