[Pythonmac-SIG] Locale and number formatting

[Ned Deily]

In article <C45AFD5C.488CC%jaharmi at jaharmi.com>,
 Jeremy Reichman <jaharmi at jaharmi.com> wrote:

> I came across the locale module, which looks as if it will do what I want
> and perform number formatting (with groupings separated by commas) for a
> report I'm trying to generate. It always seems that there's a module for
> everything I want to do.
> 
> I'm seeking output like:
> 
> '1,234.56'
> '12,345,678,910,111,213,141,516'
> 
> However, the default Python 2.5.1 in Leopard is not formatting numbers for
> me in a script. I've also seen the same results from the shell. For example:
> 
> $ python -c 'import locale; print locale.getdefaultlocale(); print
> locale.format("%8.2f", 1234.56, 3)'
> ('en_US', 'UTF8')
>  1234.56
> $ python -c 'import locale; print locale.getdefaultlocale(); print
> locale.format("%d", 12345678910111213141516, 3)'
> ('en_US', 'UTF8')
> 12345678910111213141516
> 
> I've tried this with and without a call to 'locale.setlocale(locale.LC_ALL,
> "")' as I have seen in some examples.

It looks like you just need to set LC_NUMERIC, as in:

Python 2.5.1 (r251:54863, Jan 17 2008, 19:35:17) 
[GCC 4.0.1 (Apple Inc. build 5465)] on darwin
>>> import locale
>>> print locale.localeconv()
{'mon_decimal_point': '', 'int_frac_digits': 127, 'p_sep_by_space': 127, 
'frac_digits': 127, 'thousands_sep': '', 'n_sign_posn': 127, 
'decimal_point': '.', 'int_curr_symbol': '', 'n_cs_precedes': 127, 
'p_sign_posn': 127, 'mon_thousands_sep': '', 'negative_sign': '', 
'currency_symbol': '', 'n_sep_by_space': 127, 'mon_grouping': [], 
'p_cs_precedes': 127, 'positive_sign': '', 'grouping': []}
>>> print locale.format("%8.2f", 1234.56, True)
 1234.56
>>> locale.setlocale(locale.LC_NUMERIC, 'en_US')
'en_US'
>>> print locale.localeconv()
{'mon_decimal_point': '', 'int_frac_digits': 127, 'p_sep_by_space': 127, 
'frac_digits': 127, 'thousands_sep': ',', 'n_sign_posn': 127, 
'decimal_point': '.', 'int_curr_symbol': '', 'n_cs_precedes': 127, 
'p_sign_posn': 127, 'mon_thousands_sep': '', 'negative_sign': '', 
'currency_symbol': '', 'n_sep_by_space': 127, 'mon_grouping': [], 
'p_cs_precedes': 127, 'positive_sign': '', 'grouping': [3, 3, 0]}
>>> print locale.format("%8.2f", 1234.56, True)
1,234.56
>>> print locale.format("%8.2f", 1234.56, False)
 1234.56

-- 
 Ned Deily,
 nad at acm.org