Outsmarting context managers with coroutines

output2

enter 1
enter 2
2 yo
exit  1 (<type 'exceptions.Exception'>, Exception(), <traceback object at 0x6c7b48>)

hey

output2-fix

enter 1
enter 2
2 yo
exit  2 (<type 'exceptions.Exception'>, Exception(), <traceback object at 0x7fdd928e6bd8>)
exit  1 (<type 'exceptions.Exception'>, Exception(), <traceback object at 0x7fdd928e6c68>)

hey

output3

enter 1
enter 2
2 yo
exit  1 (<class 'Exception'>, Exception(), <traceback object at 0x7f54fd7c96c8>)

exit  2 (<class 'GeneratorExit'>, GeneratorExit(), <traceback object at 0x7f54fd7c9b00>)
hey

output3-yf

enter 1
enter 2
2 yo
exit  2 (<class 'Exception'>, Exception(), <traceback object at 0x7f4449629830>)
exit  1 (<class 'Exception'>, Exception(), <traceback object at 0x7f4449629878>)

hey

outsmart2-fix.py

#!/usr/bin/env python2

from __future__ import print_function
from inspect import isgenerator

def coroutine(func):
    def start(*args, **kwargs):
        ret = func(*args, **kwargs)
        try:
            next(ret)
        except StopIteration:
            return None
        return ret
    return start

class Cmgr(object):
    def __init__(self, no):
        self.no = no
    def __enter__(self):
        print("enter", self.no)
    def __exit__(self, *args):
        print("exit ", self.no, args)

@coroutine
def yo_gen2():
    with Cmgr(2):
        while True:
            val = yield
            print(2, val)

@coroutine
def yo_gen():
    with Cmgr(1):
        ret = yo_gen2()
        if isgenerator(ret):
            try:
                while True:
                    val = yield
                    ret.send(val)
            except Exception as e:
                try:
                    ret.throw(e)
                except:
                    pass
                finally:
                    raise

gen = yo_gen()
gen.send("yo")
try:
    gen.throw(Exception())
except Exception as e:
    print(e)

a = raw_input('hey')

outsmart2.py

#!/usr/bin/env python2
from __future__ import print_function

def coroutine(func):
    def start(*args, **kwargs):
        ret = func(*args, **kwargs)
        try:
            next(ret)
        except StopIteration:
            return None
        return ret
    return start

class Cmgr(object):
    def __init__(self, no):
        self.no = no
    def __enter__(self):
        print("enter", self.no)
    def __exit__(self, *args):
        print("exit ", self.no, args)

@coroutine
def yo_gen2():
    with Cmgr(2):
        while True:
            val = yield
            print(2, val)

@coroutine
def yo_gen():
    with Cmgr(1):
        ret = yo_gen2()
        while True:
            val = yield
            ret.send(val)

gen = yo_gen()
gen.send("yo")
try:
    gen.throw(Exception())
except Exception as e:
    print(e)

a = raw_input('hey')

outsmart3-yf.py

#!/usr/bin/env python3

from __future__ import print_function

def coroutine(func):
    def start(*args, **kwargs):
        ret = func(*args, **kwargs)
        try:
            next(ret)
        except StopIteration:
            return None
        return ret
    return start

class Cmgr(object):
    def __init__(self, no):
        self.no = no
    def __enter__(self):
        print("enter", self.no)
    def __exit__(self, *args):
        print("exit ", self.no, args)

def yo_gen2():
    with Cmgr(2):
        while True:
            val = yield
            print(2, val)

@coroutine
def yo_gen():
    with Cmgr(1):
        yield from yo_gen2()

gen = yo_gen()
gen.send("yo")
try:
    gen.throw(Exception())
except Exception as e:
    print(e)

a = input('hey')

outsmart3.py

#!/usr/bin/env python3
from __future__ import print_function

def coroutine(func):
    def start(*args, **kwargs):
        ret = func(*args, **kwargs)
        try:
            next(ret)
        except StopIteration:
            return None
        return ret
    return start

class Cmgr(object):
    def __init__(self, no):
        self.no = no
    def __enter__(self):
        print("enter", self.no)
    def __exit__(self, *args):
        print("exit ", self.no, args)

@coroutine
def yo_gen2():
    with Cmgr(2):
        while True:
            val = yield
            print(2, val)

@coroutine
def yo_gen():
    with Cmgr(1):
        ret = yo_gen2()
        while True:
            val = yield
            ret.send(val)

gen = yo_gen()
gen.send("yo")
try:
    gen.throw(Exception())
except Exception as e:
    print(e)

a = input('hey')