How to sort alpha numeric set in python

Question

I have a set

set(['booklet', '4 sheets', '48 sheets', '12 sheets']) 

After sorting I want it to look like

4 sheets, 12 sheets, 48 sheets, booklet 

Any idea please

Answer 1

Jeff Atwood talks about natural sort and gives an example of one way to do it in Python. Here is my variation on it:

import re   def sorted_nicely( l ):      """ Sort the given iterable in the way that humans expect."""      convert = lambda text: int(text) if text.isdigit() else text      alphanum_key = lambda key: [ convert(c) for c in re.split('([0-9]+)', key) ]      return sorted(l, key = alphanum_key) 

Use like this:

s = set(['booklet', '4 sheets', '48 sheets', '12 sheets']) for x in sorted_nicely(s):     print(x) 

Output:

4 sheets 12 sheets 48 sheets booklet 

One advantage of this method is that it doesn't just work when the strings are separated by spaces. It will also work for other separators such as the period in version numbers (for example 1.9.1 comes before 1.10.0).