Incompatible signatures of new and init

Reports incompatible signatures of the __new__ and __init__ methods.

Example:

class MyClass(object):
    def __new__(cls, arg1):
        return super().__new__(cls)

    def __init__(self):
        pass

If the __new__ and __init__ have different arguments, then the MyClass cannot be instantiated.

As a fix, the IDE offers to apply the Change Signature refactoring.

Locating this inspection

By ID

Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.

PyInitNewSignature

Via Settings dialog

Path to the inspection settings via IntelliJ Platform IDE Settings dialog, when you need to adjust inspection settings directly from your IDE.

Settings or Preferences | Editor | Inspections | Python

Inspection ID: PyInitNewSignatureInspection

Suppressing Inspection

You can suppress this inspection by placing the following comment marker before the code fragment where you no longer want messages from this inspection to appear:

//noinspection PyInitNewSignature

More detailed instructions as well as other ways and options that you have can be found in the product documentation:

Inspection Details
By default bundled with:	CLion 2025.2, DataSpell 2025.2, IntelliJ IDEA 2025.2, PyCharm 2025.2, Qodana for JVM 2025.2,

Last modified: 18 September 2025

Incompatible signatures of __new__ and __init__

Locating this inspection

Suppressing Inspection

Incompatible signatures of new and init