Why does pycharm propose to change method to static

Question

The new pycharm release  3 1 3 community edition  proposes to convert the methods that don t work with the current object s state to static     What is the practical reason for that  Some kind of micro-performance -or-memory -optimization

User · Answer

Rather than implementing another method just to work around this error in a particular IDE  does the following make sense  PyCharm doesn t suggest anything with this implementation  class Animal      def   init   self           print  quot Animal created quot        def eat self           not self    lt -- This line here         print  quot I am eating quot     my animal   Animal

User · Answer

I can imagine following advantages of having a class method defined as static one    you can call the method just using class name  no need to instantiate it    remaining advantages are probably marginal if present at all    might run a bit faster save a bit of memory

User · Answer

The reason why Pycharm make it as a warning because Python will pass self as the first argument when calling a none static method  not add  staticmethod   Pycharm knows it   Example   class T      def test            print  i am a normal method    t   T   t test   output  Traceback  most recent call last     File  F  Workspace test script test py   line 28  in  lt module gt      T   test   TypeError  test   takes no arguments  1 given    I m from Java  in Java  self  is called  this   you don t need write self or this  as argument in class method  You can just call self as you need inside the method  But Python  has to  pass self as a method argument   By understanding this you don t need any Workaround as  BobStein answer

User · Answer

Since you didn t refer to self in the bar method body  PyCharm is asking if you might have wanted to make bar static  In other programming languages  like Java  there are obvious reasons for declaring a static method  In Python  the only real benefit to a static method  AFIK  is being able to call it without an instance of the class  However  if that s your only reason  you re probably better off going with a top-level function - as note here   In short  I m not one hundred percent sure why it s there  I m guessing they ll probably remove it in an upcoming release

User · Answer

It might be a bit messy  but sometimes you just don t need to access self  but you would prefer to keep the method in the class and not make it static  Or you just want to avoid adding a bunch of unsightly decorators  Here are some potential workarounds for that situation   If your method only has side effects and you don t care about what it returns   def bar self       doing something without self       return self   If you do need the return value   def bar self       result   doing something without self       if self          return result   Now your method is using self  and the warning goes away

User · Answer

This error message just helped me a bunch  as I hadn t realized that I d accidentally written my function using my testing example player  my player attributes item     instead of the correct way  self attributes item

User · Answer

I agree with the answers given here  method does not use self and therefore could be decorated with  staticmethod    I d like to add that you maybe want to move the method to a top-level function instead of a static method inside a class  For details see this question and the accepted answer  python - should I use static methods or top-level functions  Moving the method to a top-level function will fix the PyCharm warning  too

User · Answer

Agreed with  jolvi   ArundasR  and others  the warning happens on a member function that doesn t use self   If you re sure PyCharm is wrong  that the function should not be a  staticmethod  and if you value zero warnings  you can make this one go away two different ways   Workaround  1  def bar self       self is not used       doing something without self    def is not used self       pass   Workaround  2  Thanks  DavidP  rsson     noinspection PyMethodMayBeStatic def bar self       doing something without self     The application I had for this  the reason I could not use  staticmethod  was in making a table of handler functions for responding to a protocol subtype field   All handlers had to be the same form of course  static or nonstatic    But some didn t happen to do anything with the instance   If I made those static I d get  TypeError   staticmethod  object is not callable    In support of the OP s consternation  suggesting you add staticmethod whenever you can  goes against the principle that it s easier to make code less restrictive later  than to make it more -- making a method static makes it less restrictive now  in that you can call class f   instead of instance f       Guesses as to why this warning exists    It advertises staticmethod   It makes developers aware of something they may well have intended  As  JohnWorrall s points out  it gets your attention when self was inadvertently left out of the function    It s a cue to rethink the object model  maybe the function does not belong in this class at all

User · Answer

PyCharm  thinks  that you might have wanted to have a static method  but you forgot to declare it to be static  using the  staticmethod decorator     PyCharm proposes this because the method does not use self in its body and hence does not actually change the class instance  Hence the method could be static  i e  callable without passing a class instance or without even having created a class instance

User · Answer

I think that the reason for this warning is config in Pycharm  You can uncheck the selection Method may be static in Editor- Inspection

[python] Why does pycharm propose to change method to static

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