Python Pocket Reference, 3rd Edition

Other Built-in Modules

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The datetime Module

Tools for subtracting dates, adding days to dates, and so on.

See the Python Library Manual for details.

from datetime import date, timedelta

>>> date(2004, 12, 17) - date(2004, 11, 29)

datetime.timedelta(18)

>>> date(2004, 11, 29) + timedelta(18)

datetime.date(2004, 12, 17)

Threading Modules

Threads are lightweight processes that share global memory

(i.e., lexical scopes and interpreter internals) and all run in

parallel within the same process. Python thread modules

work portably across platforms.

thread

Python’s basic thread interface module. Tools to start,

stop, and synchronize functions run in parallel. To

spawn a thread:

thread.start_new_thread(function,

argstuple)

. Function start_new is a synonym for start_

new_thread

. To synchronize threads, use thread locks:

lock=thread.allocate_lock(); lock.acquire(); update-

objects

; lock.release().

threading

Module threading builds upon thread, to provide thread-

ing-oriented classes:

Thread, Condition, Semaphore, Lock,

etc. Subclass

Thread to overload run action method.

Queue

A multiproducer, multiconsumer FIFO queue of objects

implementation, especially useful for threaded applica-

tions (see the Python Library Reference). Locks

get and

put operations to synchronize access to data on the

queue.