Python analog of PHP's natsort function (sort a list using a "natural order" algorithm) [duplicate]

Question

I would like to know if there is something similar to PHP natsort function in Python?

l = ['image1.jpg', 'image15.jpg', 'image12.jpg', 'image3.jpg'] l.sort() 

gives:

['image1.jpg', 'image12.jpg', 'image15.jpg', 'image3.jpg'] 

but I would like to get:

['image1.jpg', 'image3.jpg', 'image12.jpg', 'image15.jpg'] 

UPDATE

Solution base on this link

def try_int(s):     "Convert to integer if possible."     try: return int(s)     except: return s  def natsort_key(s):     "Used internally to get a tuple by which s is sorted."     import re     return map(try_int, re.findall(r'(\d+|\D+)', s))  def natcmp(a, b):     "Natural string comparison, case sensitive."     return cmp(natsort_key(a), natsort_key(b))  def natcasecmp(a, b):     "Natural string comparison, ignores case."     return natcmp(a.lower(), b.lower())  l.sort(natcasecmp); 

Answer 1

From my answer to Natural Sorting algorithm:

import re def natural_key(string_):     """See https://blog.codinghorror.com/sorting-for-humans-natural-sort-order/"""     return [int(s) if s.isdigit() else s for s in re.split(r'(\d+)', string_)] 

Example:

>>> L = ['image1.jpg', 'image15.jpg', 'image12.jpg', 'image3.jpg'] >>> sorted(L) ['image1.jpg', 'image12.jpg', 'image15.jpg', 'image3.jpg'] >>> sorted(L, key=natural_key) ['image1.jpg', 'image3.jpg', 'image12.jpg', 'image15.jpg'] 

To support Unicode strings, .isdecimal() should be used instead of .isdigit(). See example in @phihag's comment. Related: How to reveal Unicodes numeric value property.

.isdigit() may also fail (return value that is not accepted by int()) for a bytestring on Python 2 in some locales e.g., '\xb2' ('²') in cp1252 locale on Windows.