Add thousands separator support when LOCALE is enabled.

[madphysicist]

This issue was discovered when I tried to suggest natsort as the way to go for this Stack Overflow question: http://stackoverflow.com/q/36431810/2988730

I was trying to do the following based on the docs:

import natsort, locale
locale.setlocale(locale.LC_ALL, 'german')
mylist = ['23 text', '23.130', '12 text', '1.482 text', '3,25']
natsort.humansorted(mylist)

or alternatively

natsort.natsorted(mylist, alg=natsort.ns.LOCALE)

The result in both cases is

['1.482 text', '3,25', '12 text', '23.130', '23 text']

The result that the OP (correctly) expected is

['3,25', '12 text', '23 text', '1.482 text', '23.130']

It appears that natsort is not picking up the locale correctly?

I am using Red Hat Enterprise Linux Release 6.5 (64 bit) with anaconda. natsort 4.0.3 is running under Python 3.5.

Also, just to check that the locale is being set, I ran locale.localeconv after locale.setlocale(locale.LC_ALL, 'german'):

{'currency_symbol': 'EUR',
 'decimal_point': ',',
 'frac_digits': 2,
 'grouping': [3, 3, 0],
 'int_curr_symbol': 'EUR ',
 'int_frac_digits': 2,
 'mon_decimal_point': ',',
 'mon_grouping': [3, 3, 0],
 'mon_thousands_sep': '.',
 'n_cs_precedes': 0,
 'n_sep_by_space': 1,
 'n_sign_posn': 1,
 'negative_sign': '-',
 'p_cs_precedes': 0,
 'p_sep_by_space': 1,
 'p_sign_posn': 1,
 'positive_sign': '',
 'thousands_sep': '.'}

[SethMMorton]

Natsort currently does not support thousands separators. It does understand the difference in the decimal point, but that's not the issue here. The problem is that it is unclear in general if something is supposed to be a thousands separator or not. For example, if a user provides "14,57 x,y" they would not want it treated as the thousands separator.

I would be in support of adding a flag to enable this, but not turning it on by default as I would be afraid it would break other people's code.

[madphysicist]

That makes sense. I will take a look.

[SethMMorton]

I am in the middle of refactoring natsort to make it easier to add new features. I will add this functionality after I have completed the refactor.

[SethMMorton]

OK, version 5.0.0 is released and this functionality is now part of the LOCALE option (and thus also the humansorted function).

Feel free to add natsort to that SO question if you want now 😄

[madphysicist]

Thanks. I certainly will. This library deserves to have good publicity.

[SethMMorton]

Thanks, I appreciate that.