将参数传递给 Python 中的函数

Question

I'm not sure why I'm getting the message error

TypeError: __init__() takes exactly 3 arguments (4 given)

for the code described below:

class Worker(object):
    def __init__(arg1,arg2,arg3):
        self.arg1 = arg1
        self.arg2 = arg2
        self.arg3 = arg3
    def some_function(self):
        print "it works: " + arg1 + arg2 + arg3

w=Worker("a","b","c")
w.some_function()

What could I be missing?

Answer 1

It should be def __init__(self, arg1,arg2,arg3): . You'll also need to change the print statement in some_function to

print "it works: " + self.arg1 + self.arg2 + self.arg3

Answer 2

def __init__(self,arg1,arg2,arg3):

Answer 3

The first argument expected for any class function should always be self .

Well, the name is unimportant, but that's the meaning of it.

So your function definintion should look like:

def __init__(self,arg1,arg2,arg3): 
    self.arg1 = arg1 
    self.arg2 = arg2 
    self.arg3 = arg3