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);
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.