correct way to define class variables in Python

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Top 5 Answer for correct way to define class variables in Python

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Neither way is necessarily correct or incorrect, they are just two different kinds of class elements:

  • Elements outside the __init__ method are static elements; they belong to the class.
  • Elements inside the __init__ method are elements of the object (self); they don't belong to the class.

You'll see it more clearly with some code:

class MyClass:     static_elem = 123      def __init__(self):         self.object_elem = 456  c1 = MyClass() c2 = MyClass()  # Initial values of both elements >>> print c1.static_elem, c1.object_elem  123 456 >>> print c2.static_elem, c2.object_elem 123 456  # Nothing new so far ...  # Let's try changing the static element MyClass.static_elem = 999  >>> print c1.static_elem, c1.object_elem 999 456 >>> print c2.static_elem, c2.object_elem 999 456  # Now, let's try changing the object element c1.object_elem = 888  >>> print c1.static_elem, c1.object_elem 999 888 >>> print c2.static_elem, c2.object_elem 999 456 

As you can see, when we changed the class element, it changed for both objects. But, when we changed the object element, the other object remained unchanged.

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I think this sample explains the difference between the styles:

james@bodacious-wired:~$cat  #!/usr/bin/env python  class MyClass:     element1 = "Hello"      def __init__(self):         self.element2 = "World"  obj = MyClass()  print dir(MyClass) print "--" print dir(obj) print "--" print obj.element1  print obj.element2 print MyClass.element1 + " " + MyClass.element2 james@bodacious-wired:~$./  ['__doc__', '__init__', '__module__', 'element1'] -- ['__doc__', '__init__', '__module__', 'element1', 'element2'] -- Hello World Hello Traceback (most recent call last):   File "./", line 17, in <module>     print MyClass.element2 AttributeError: class MyClass has no attribute 'element2' 

element1 is bound to the class, element2 is bound to an instance of the class.

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as suggested in git status,

Unmerged paths:                                                                                                                                 (use "git add <file>..." to mark resolution)                                                                                                       both modified:   a.jl                                       both modified:   b.jl 

I used git add to finish the merging, then git checkout works fine.

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my issue was (master|REBASE 1/1)

this command worked for me

 git rebase --skip 
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I had the same issue when switching from a dev branch to master branch. What I did was commit my changes and switch to the master branch. You might have uncommitted changes.

And also you can try this git reset --merge as well. This can be used to resolve any conflicts and revert.

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