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<H2><A NAME="SECTION00121020000000000000000">
10.10.2 Examples</A>
</H2>
<P>
Here are two example sessions (one using the command line, one using
the module interface) that compare the cost of using
<tt class="function">hasattr()</tt> vs. <tt class="keyword">try</tt>/<tt class="keyword">except</tt> to test for
missing and present object attributes.
<P>
<div class="verbatim"><pre>
% timeit.py 'try:' ' str.__nonzero__' 'except AttributeError:' ' pass'
100000 loops, best of 3: 15.7 usec per loop
% timeit.py 'if hasattr(str, "__nonzero__"): pass'
100000 loops, best of 3: 4.26 usec per loop
% timeit.py 'try:' ' int.__nonzero__' 'except AttributeError:' ' pass'
1000000 loops, best of 3: 1.43 usec per loop
% timeit.py 'if hasattr(int, "__nonzero__"): pass'
100000 loops, best of 3: 2.23 usec per loop
</pre></div>
<P>
<div class="verbatim"><pre>
>>> import timeit
>>> s = """\
... try:
... str.__nonzero__
... except AttributeError:
... pass
... """
>>> t = timeit.Timer(stmt=s)
>>> print "%.2f usec/pass" % (1000000 * t.timeit(number=100000)/100000)
17.09 usec/pass
>>> s = """\
... if hasattr(str, '__nonzero__'): pass
... """
>>> t = timeit.Timer(stmt=s)
>>> print "%.2f usec/pass" % (1000000 * t.timeit(number=100000)/100000)
4.85 usec/pass
>>> s = """\
... try:
... int.__nonzero__
... except AttributeError:
... pass
... """
>>> t = timeit.Timer(stmt=s)
>>> print "%.2f usec/pass" % (1000000 * t.timeit(number=100000)/100000)
1.97 usec/pass
>>> s = """\
... if hasattr(int, '__nonzero__'): pass
... """
>>> t = timeit.Timer(stmt=s)
>>> print "%.2f usec/pass" % (1000000 * t.timeit(number=100000)/100000)
3.15 usec/pass
</pre></div>
<P>
To give the <tt class="module">timeit</tt> module access to functions you
define, you can pass a <code>setup</code> parameter which contains an import
statement:
<P>
<div class="verbatim"><pre>
def test():
"Stupid test function"
L = []
for i in range(100):
L.append(i)
if __name__=='__main__':
from timeit import Timer
t = Timer("test()", "from __main__ import test")
print t.timeit()
</pre></div>
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<span class="release-info">Release 2.3.4, documentation updated on May 20, 2004.</span>
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