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| 54 | <H2><A NAME="SECTION005510000000000000000"></A><A NAME="atexit-example"></A> |
| 55 | <BR> |
| 56 | 3.5.1 <tt class="module">atexit</tt> Example |
| 57 | </H2> |
| 58 | |
| 59 | <P> |
| 60 | The following simple example demonstrates how a module can initialize |
| 61 | a counter from a file when it is imported and save the counter's |
| 62 | updated value automatically when the program terminates without |
| 63 | relying on the application making an explicit call into this module at |
| 64 | termination. |
| 65 | |
| 66 | <P> |
| 67 | <div class="verbatim"><pre> |
| 68 | try: |
| 69 | _count = int(open("/tmp/counter").read()) |
| 70 | except IOError: |
| 71 | _count = 0 |
| 72 | |
| 73 | def incrcounter(n): |
| 74 | global _count |
| 75 | _count = _count + n |
| 76 | |
| 77 | def savecounter(): |
| 78 | open("/tmp/counter", "w").write("%d" % _count) |
| 79 | |
| 80 | import atexit |
| 81 | atexit.register(savecounter) |
| 82 | </pre></div> |
| 83 | |
| 84 | <P> |
| 85 | Positional and keyword arguments may also be passed to |
| 86 | <tt class="function">register()</tt> to be passed along to the registered function |
| 87 | when it is called: |
| 88 | |
| 89 | <P> |
| 90 | <div class="verbatim"><pre> |
| 91 | def goodbye(name, adjective): |
| 92 | print 'Goodbye, %s, it was %s to meet you.' % (name, adjective) |
| 93 | |
| 94 | import atexit |
| 95 | atexit.register(goodbye, 'Donny', 'nice') |
| 96 | |
| 97 | # or: |
| 98 | atexit.register(goodbye, adjective='nice', name='Donny') |
| 99 | </pre></div> |
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