使用python2.X的locale模块格式化数字和货币

任务是将数字、货币金额和日期格式化为 unicode 以区域设置感知的方式创建字符串。

第一次天真的数字尝试带来了希望:

Python 2.7 (r27:82525, Jul  4 2010, 09:01:59) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import locale
>>> locale.setlocale(locale.LC_ALL, '')
'English_Australia.1252'
>>> locale.format("%d", 12345678, grouping=True)
'12,345,678'
>>> locale.format(u"%d", 12345678, grouping=True)
u'12,345,678'
>>>

>>> locale.setlocale(locale.LC_ALL, 'French_France')
'French_France.1252'
>>> locale.format("%d", 12345678, grouping=True)
'12\xa0345\xa0678'
>>> locale.format(u"%d", 12345678, grouping=True)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\python27\lib\locale.py", line 190, in format
    return _format(percent, value, grouping, monetary, *additional)
  File "C:\python27\lib\locale.py", line 211, in _format
    formatted, seps = _group(formatted, monetary=monetary)
  File "C:\python27\lib\locale.py", line 160, in _group
    left_spaces + thousands_sep.join(groups) + right_spaces,
UnicodeDecodeError: 'ascii' codec can't decode byte 0xa0 in position 0: ordinal not in range(128)

这里发生了什么?

>>> locale.localeconv() # output edited for brevity
{'thousands_sep': '\xa0', 'mon_thousands_sep': '\xa0', 'currency_symbol': '\x80'}

>>> locale.format("%d", 12345678, grouping=True).decode(locale.getpreferredencoding())
u'12\xa0345\xa0678'
>>>

更新1 locale.getpreferredencoding() 是 走的路;使用 locale.getlocale()[1]

Python 2.7 (r27:82525, Jul  4 2010, 09:01:59) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import locale
>>> locale.getpreferredencoding(), locale.getlocale()
('cp1252', (None, None))
>>> locale.setlocale(locale.LC_ALL, '')
'English_Australia.1252'
>>> locale.getpreferredencoding(), locale.getlocale()
('cp1252', ('English_Australia', '1252'))
>>> locale.setlocale(locale.LC_ALL, 'russian_russia')
'Russian_Russia.1251'
>>> locale.getpreferredencoding(), locale.getlocale()
('cp1252', ('Russian_Russia', '1251')) #### Whoops! ####
>>>

更新2

>>> locale.setlocale(locale.LC_ALL, 'french_france')
'French_France.1252'
>>> format(12345678, 'n')
'12\xa0345\xa0678'
>>> format(12345678, u'n') # type triggers cast to unicode somehow
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
UnicodeDecodeError: 'ascii' codec can't decode byte 0xa0 in position 2: ordinal not in range(128)
>>> import datetime;datetime.date(1999,12,31).strftime(u'%B') # type is ignored
'd\xe9cembre'
>>>

在所有情况下,解决方法都是只使用 str 对象调用这些方法时,获取 结果,并使用 语言环境.getlocale()[1]

(1) 当测试/探索Windows语言环境名称不仅不同于POSIX(“frïfr”),而且冗长且没有完整的文档时,这是一个相当麻烦的问题。例如,印度的分组显然不是“每3位数”。。。我找不到用来探索这个问题的语言环境;像“印地语”和“印地语-印度”这样的尝试是行不通的。

(2) 有些localeconv()数据是完全错误的。例如,对于韩语,货币符号如下所示 '\\' i、 一个反斜杠。我知道一些7位遗留字符集不兼容ASCII,chr(92)有时被用作本地货币符号,所以我预计 '\\' .decode('949')生成赢的符号,而不仅仅是 u'\\'

babel 但我并不是特别想强加这样一个巨大的外部依赖。我能同时得到正确和方便吗?有什么关于 locale 我错过的模块?