natural sort

http://stackoverflow.com/
から。

import numpy as np

import re
def atoi(text):

    try:

        return int(text)

    except ValueError:

        return text
def natural_keys(text):

    '''

    alist.sort(key=natural_keys) sorts in human order

    http://nedbatchelder.com/blog/200712/human_sorting.html

    '''    

    return [ atoi(c) for c in re.split('([-]?\d+)', text) ]
a = np.array(["3", "-2", "-1", "0", "2", "word"])

print(sorted(a,key=natural_keys))

# ['-2', '-1', '0', '2', '3', 'word']
a = np.array(["3", "-2", "-1", "0", "2", "word", "-1 word", "-2 up"])

print(sorted(a,key=natural_keys))

# ['-2', '-2 up', '-1', '-1 word', '0', '2', '3', 'word']