Python_3_Call_a_class_like_a_function.md

Python 3(atleast?) got a neat __call__ method for classes, which you can use to call a class like a function!

This is awesome, because now it's possible for us to treat a class like a function. Example class:

class example:
  def __init__(self, say=u"Hello World!"):
    self.phrase=say
    print(u"__init__(self, say=u\"{}\")".format(self.phrase))
  
  def say(self):
    print(self.phrase)
x=example()
x.say()

The output is simple:

__init__(self, say=u"Hello World!")

Now adding __call__ to call the instance of the object!

We can now add __call__ to call the instance of the object as a function itself:

class example:
  def __init__(self, say=u"Hello World!"):
    self.phrase=say
    print(u"__init__(self, say=u\"{}\")".format(self.phrase))
  
  def say(self):
    print(self.phrase)
  
  def __call__(self, say):
    self.phrase=say
    print(u"__call__(self, say=u\"{}\")".format(self.phrase))
    self.say()

xmpl=example()
xmpl.say()
xmpl(u"new Hello World!")

Output:

__init__(self, say=u"Hello World!")
Hello World!
__call__(self, say=u"new Hello World!")
new Hello World!