问题
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Python 'self' keyword
Forgive me if this is an incredibly noobish question, but I never did understand self in Python. What does it do? And when I see things like
def example(self, args):
return self.something
what do they do? I think I've seen args somewhere in a function too. Please explain in a simple way :P
回答1:
It sounds like you've stumbled onto the object oriented features of Python.
self is a reference to an object. It's very close to the concept of this in many C-style languages. Check out this code:
class Car(object):
def __init__(self, make):
# Set the user-defined 'make' property on the self object
self.make = make
# Set the 'horn' property on the 'self' object to 'BEEEEEP'
self.horn = 'BEEEEEP'
def honk(self):
# Now we can make some noise!
print self.horn
# Create a new object of type Car, and attach it to the name `lambo`.
# `lambo` in the code below refers to the exact same object as 'self' in the code above.
lambo = Car('Lamborghini')
print lambo.make
lambo.honk()
回答2:
self is the reference to the instance of the class that the method (the example function in this case) is of.
You'll want to take a look at the Python docs on the class system for a full introduction to Python's class system. You'll also want to look at these answers to other questions about the subject on Stackoverflow.
回答3:
Self it a reference to the instance of the current class. In your example, self.something references the something property of the example class object.
来源：https://stackoverflow.com/questions/6698030/what-does-self-do