Access class instance from one file in another file?

I have two files, both are in the same project (part of a web scraping framework). File1 processes items that are generated by File2. In File2 I have a function that prints out some basic stats about the processes (counts of how many items have been generated, etc). I have counts in File1 that I would like to print with the stats from File1 but am unsure of how to do that. Take a look at the example code.

FILE 1:

class Class1(object):
    def __init__(self):
        self.stats = co开发者_JAVA技巧unter("name") #This is the instance that I'd like to use in File2
        self.stats.count = 10

class counter:
    def __init__(self, name):
        self.name = name
        self.count = 0
    def __string__(self):
        message = self.name + self.count
        return message

FILE 2: (this is what I'd like to do)

from project import file1 # this import returns no error

def stats():
    print file1.Class1.stats # This is where I'm trying to get the instance created in Class1 of File2.
    #print file1.Class1.stats.count # Furthermore, it would be nice if this worked too.

ERROR:

exceptions.AttributeError: type object 'Class1' has no attribute 'stats'

I know that both files are running, thus so does the 'stats' instance of the 'counter' class, because of other methods being printed out when running the project (this is just a stripped down example. What am I doing wrong here? Is this possible to do?

This is not working because you never instantiate Class1.

__init__ is called when the Class1 is instantiated so Class1.stats is set.

You have 2 options here.

1. instantiate Class1 in file 2 somehow.
2. declare a static method in Class1 that returns the count property.

Your terminology is a little mixed up. "both files are running, thus so does the 'stats' instance of the 'counter' class" - stats is a attribute of objects of the counter class. If you want a count of how many instances of the class are created, you should use a class attribute which is something that is bound to your class, and not an instance of it.

class Counter(object):
    count = 0

    def __init__(self, name):
        self.name = name
        Counter.count += 1
        self.id = Counter.count

    def __repr__(self):
        return '<Counter: %s (%d of %d)>' % (
            self.name, self.id, Counter.count)

So then this can be used like so,

>>> foo = Counter('Foo')
>>> print foo
<Counter: Foo (1 of 1)>
>>> bar = Counter('Bar')
>>> print bar
<Counter: Bar (2 of 2)>
>>> print foo
<Counter: Foo (1 of 2)>
>>>

Note that the second time you print foo it has updated the count, but the id remains the same, that is because count is a class attribute, but id is an attribute of the object, so (with this code) the creation of bar doesn't affect the id of foo, but it increments Counter.count.

In File1, create an instance of Class1, and use that to get the count.

class Class1(object):
    def __init__(self):
        self.stats = counter()
        self.stats.count = 10

class counter:
    def __init__(self, name):
        self.name = name
        self.count = 0
    def __string__(self):
        message = self.name + self.count
        return message

class_instance = Class1()

In file2, use the created instance:

from project import file1

def stats():
    print file1.class_instance.stats