class MyClass:
var1 = 1
def update(value):
MyClass.var1 += value
def __init__(self,value):
self.value = value
MyClass.update(value)
a = MyClass(1)
I'm trying to update a class variable(var1) within a method(_init_) but I gives me:
TypeError: unbound method update() must be called with MyClass instance as first argument (got int instance instead)
I'm doing this because I want easy access to all variables in a class by calling print MyClass.var1
You are confusing classes and instances.
class MyClass(object):
pass
a = MyClass()
MyClass is a class, a is an instance of that class. Your error here is that update is an instance method. To call it from __init__, use either:
self.update(value)
or
MyClass.update(self, value)
Alternatively, make update a class method:
@classmethod
def update(cls, value):
cls.var1 += value
You need to use the @classmethod decorator:
$ cat t.py
class MyClass:
var1 = 1
@classmethod
def update(cls, value):
cls.var1 += value
def __init__(self,value):
self.value = value
self.update(value)
a = MyClass(1)
print MyClass.var1
$ python t.py
2
