Conditional "with" context manager

gistfile1.txt

"""
Python3 conditional locking example
"""

from threading import Lock
lock = Lock()

class ConditionalLock(object):
    """silly example to test locking via context manager"""

    def __init__(self, lockrequest=True, verbose=False):
        self.lockrequest = lockrequest
        self.verbose = verbose

    def __enter__(self):
        if self.lockrequest:
            if self.verbose:
                print("I'd better be locking, then.")
            lock.acquire()
            if self.verbose:
                print("Success: Lock acquired!")
        else:
            if self.verbose:
                print("I will do no locking")

    def __exit__(self, exc_type, exc_value, traceback):
        if self.lockrequest:
            if self.verbose:
                print("Unlocking attempt in progress.")
            lock.release()
            if self.verbose:
                print("Success. The lock is history.")
        else:
            if self.verbose:
                print("No need to do any unlocking")


if __name__ == '__main__':

    with ConditionalLock(lockrequest=False, verbose=True):
        print('I am working!')

    with ConditionalLock(lockrequest=True, verbose=True):
        print('I am working with a lock!')
        try:
            raise RuntimeError('Ooops!')
        except RuntimeError as e:
            print('I think I saw a runtime error')
            raise