Go interfaces and type assertions compared to Python's Abstract Base Classes

gistfile1.py

#!/usr/bin/env python

import abc


### Go equivalent
#
# type Lock interface {
#     Lock()
#     Unlock()
# }

class Lock:
    __metaclass__ = abc.ABCMeta

    @abc.abstractmethod
    def Lock():
        pass

    @abc.abstractmethod
    def Unlock():
        pass

### Go equivalent
#
# type Mutex struct {}
#
# func (m Mutex) Lock() {}
# func (m Mutex) Unlock() {}

class Mutex(object):

    def Lock():
        pass

    def Unlock():
        pass

# /!\ This is the important difference /!\
# Pyhon's abc requires explicit type registration.
Lock.register(Mutex)

### Go equivalent
#
# func main() {
#     var m Mutex
#     var o interface{} = m
#
#     res, ok := o.(Lock)
#     fmt.Println(res, ok)
# }

def type_assertion(instance, type_):
    return instance if isinstance(instance, type_) else None


if __name__ == "__main__":
    m = Mutex()
    print type_assertion(m, Lock)