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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Aaron, unlike Massimo’s elegant one-liner you don’t check that what you are iterating over is a list. Since Python will happily iterate over strings, dictionaries,
and much more you quickly get into problems when the list includes more types than lists and numbers. I recount this from experience when I tried to throw together a flatten routine and pass it a data structure that I got from loading a JSON string.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Calibri",sans-serif;color:#1F497D">Phil Robare<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><snip/><o:p></o:p></span></b></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal">On Thu, Feb 18, 2016 at 1:43 PM, Aaron Elmquist <<a href="mailto:elmq0022@umn.edu" target="_blank">elmq0022@umn.edu</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">Douglas, <o:p></o:p></p>
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<p class="MsoNormal">Here's one more version for you and the rest of the list. It's based on Brad's code. I will let you think about why this version might be better or worse. Also, recursion is great. It's just too bad it's not one of python's strong points.<o:p></o:p></p>
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<br>
def flatten(lst):<br>
for item1 in lst:<br>
if hasattr(item1, '__iter__'):<br>
for item2 in flatten(item1):<br>
yield item2<br>
else:<br>
yield item1<br>
<br>
print([x for x in flatten([1, [2,3,[4,5,6,[7,8,9]]]]) if x%2 == 1])<br>
<br>
y = flatten([1, [2,3,[4,5,6,[7,8,9]]]])<br>
<br>
print(next(y))<br>
print(next(y))<br>
print(next(y))<br>
.<br>
.<br>
.<br>
<snip/><o:p></o:p></p>
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<p class="MsoNormal">On Wed, Feb 17, 2016 at 9:48 PM, DiPierro, Massimo <<a href="mailto:MDiPierro@cs.depaul.edu" target="_blank">MDiPierro@cs.depaul.edu</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:46.2pt">here is a one liner:<br>
<br>
def flatten(x):<br>
return [z for y in x for z in flatten(y)] if isinstance(x,list) else [x]<br>
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<br>
<o:p></o:p></p>
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