How to pass a variable from a function to a class python

问题

I am trying to pass a variable from a function to a class. Example code is below:

def hello(var):

    return var

class test():
    def __init__(self):
        pass

    def value(self):
        print var

hello(var)
test = test()
test.value()

I would like to pass var into the class test().

Thanks for any help.

回答1:

You need to modify your class like this:

class test():
    def __init__(self, var):
        self.var = var

    def value(self):
        print self.var

test_inst = test(var)
test_inst.value()

Also, you cannot use the same exact name to refer to both class instance and a class itself.

回答2:

class test():
    def __init__(self, var):
        self._var = var

    def value(self):
        print self._var

回答3:

Add the statement:

global var

to your code:

>>> global var
>>> def hello():
       print var

>>> class test():
       def __init__(self):
           pass

       def value(self):
           print var

>>> var = 15
>>> hello()
15
>>> test().value()
15

Cue standard disclaimer regarding global variables are bad... but this is how you do it.

回答4:

I think you can call hello function in class's function.

def hello (var):
    return var

class test():
    def __init__(self):
        pass

    def value(self):
        var = hello(5)
        print var

test = test()
test.value()

来源：https://stackoverflow.com/questions/2766239/how-to-pass-a-variable-from-a-function-to-a-class-python