>>498
def release0():
    print 'release0: success'
    res = err = None
    return (res,err)
def release1():
    print 'release1: success'
    res = err = None
    return (res,err)
def release2():
    print 'release2: error'
    res = None
    err = "error_oppai"
    return (res,err)

release2() # ←これがエラーになるとrelease1()とrelease0()が実行されない
release1()
release0()

>実行されますが何か？
>release2: error
>release1: success
>release0: success