用于浮点转换的自定义区域设置配置

Question

我需要将"1.234.345,00"格式的字符串转换为float值{}。在

一种方法是使用repeatedstr.replace：

x = "1.234.345,00"
res = float(x.replace('.', '').replace(',', '.'))

print(res, type(res))
1234345.0 <class 'float'>

然而，这似乎是手动的和非通用的。这个heavily upvoted answer建议使用locale库。但是我的默认区域设置与输入字符串没有相同的约定。然后，我发现了一种方法，可以提取当地惯例中使用的字符作为字典：

^{pr2}$

是否有方法更新此词典，另存为自定义区域设置，然后能够继续调用此自定义区域设置。比如：

mylocale = locale.create_new_locale()  # "blank" conventions or copied from default
mylocale.localeconv()['thousands_sep'] = '.'
mylocale.localeconv()['decimal_point'] = ','

setlocale(LC_NUMERIC, mylocale)
atof('123.456,78')  # 123456.78

如果这是不可能的，我们如何获得所有可用的语言环境及其约定的列表？似乎反模式可以从约定中“推断”正确的配置（更不用说低效/手动），所以我希望有一个通用的解决方案，比如上面的伪代码。在

---

{在这里查找所有地方。实际上，更一般地说，要通过以下参数的组合对区域设置进行分组：

import locale
from collections import defaultdict

d = defaultdict(list)

for alias in locale.locale_alias:
    locale.setlocale(locale.LC_ALL, alias)
    env = locale.localeconv()
    d[(env['thousands_sep'], env['decimal_point'])].append(alias)

结果：

---------------------------------------------------------------------------
Error                                     Traceback (most recent call last)
<ipython-input-164-f8f6a6db7637> in <module>()
      5 
      6 for alias in locale.locale_alias:
----> 7     locale.setlocale(locale.LC_ALL, alias)
      8     env = locale.localeconv()
      9     d[(env['thousands_sep'], env['decimal_point'])].append(alias)

C:\Program Files\Anaconda3\lib\locale.py in setlocale(category, locale)
    596         # convert to string
    597         locale = normalize(_build_localename(locale))
--> 598     return _setlocale(category, locale)
    599 
    600 def resetlocale(category=LC_ALL):

Error: unsupported locale setting

Answer 1

{为了测试源代码，你可以看到一个源代码。在

# With this dict, you can override some items of localeconv's return value.
# This is useful for testing purposes.
_override_localeconv = {}

尝试以下操作似乎确实会在不更改整个区域设置的情况下重写字典，但可能会产生一些意外的后果，特别是因为更改区域设置不是线程安全的。小心！在

^{pr2}$

Try it online!

Answer 2

你的问题有两个部分：

1. 如何以通用方式解析“1.234.345,00”？在
2. 如何轻松找到与“1.234.345,00”关联的区域设置？在

您可以同时使用令人惊叹的Babel库。在

如何以通用方式解析“1.234.345,00”？在

与.千位分隔符和,十进制分隔符关联的一个区域设置是ger_de，用于德语。在

要解析它，只需使用

>>> from babel.numbers import parse_decimal
>>> parse_decimal('1.234.345,00', locale='ger_de')
Decimal('1234345.00')

如何轻松找到与“1.234.345,00”关联的区域设置？在

使用此例程检查要根据所有区域设置的预期值进行分析的字符串，并返回兼容的值：

^{pr2}$

例如：

>>> print(get_compatible_locales('1.234.345,00', Decimal('1234345')))
['ar_dz', 'ar_lb', 'ar_ly', 'ar_ma', 'ar_tn', 'ast_es', 'az', 'az_az', 'az_az.iso88599e', 'bs', 'bs_ba', 'ca', 'ca_ad', 'ca_es', 'ca_es@valencia', 'ca_fr', 'ca_it', 'da', 'da_dk', 'de', 'de_at', 'de_be', 'de_de', 'de_lu', 'el', 'el_cy', 'el_gr', 'el_gr@euro', 'en_be', 'en_dk', 'es', 'es_ar', 'es_bo', 'es_cl', 'es_co', 'es_ec', 'es_es', 'es_py', 'es_uy', 'es_ve', 'eu', 'eu_es', 'fo', 'fo_fo', 'fr_lu', 'fy_nl', 'ger_de', 'gl', 'gl_es', 'hr', 'hr_hr', 'hsb_de', 'id', 'id_id', 'in', 'in_id', 'is', 'is_is', 'it', 'it_it', 'kl', 'kl_gl', 'km_kh', 'lb_lu', 'lo', 'lo_la', 'lo_la.cp1133', 'lo_la.ibmcp1133', 'lo_la.mulelao1', 'mk', 'mk_mk', 'nl', 'nl_aw', 'nl_be', 'nl_nl', 'ps_af', 'pt', 'pt_br', 'ro', 'ro_ro', 'rw', 'rw_rw', 'sl', 'sl_si', 'sr', 'sr@cyrillic', 'sr@latn', 'sr_cs', 'sr_cs.iso88592@latn', 'sr_cs@latn', 'sr_me', 'sr_rs', 'sr_rs@latn', 'sr_yu', 'sr_yu.cp1251@cyrillic', 'sr_yu.iso88592', 'sr_yu.iso88595', 'sr_yu.iso88595@cyrillic', 'sr_yu.microsoftcp1251@cyrillic', 'sr_yu.utf8', 'sr_yu.utf8@cyrillic', 'sr_yu@cyrillic', 'tr', 'tr_cy', 'tr_tr', 'vi', 'vi_vn', 'vi_vn.tcvn', 'vi_vn.tcvn5712', 'vi_vn.viscii', 'vi_vn.viscii111', 'wo_sn']

额外的好处是：我怎样才能获得这些语言环境的可读版本？在

使用以下例程，其中my_locale应该是您自己的语言环境：

from babel import Locale

def get_display_name(alias, my_locale='en_US'):
    l = Locale.parse(alias)
    return l.get_display_name(my_locale)

然后可以这样使用它：

>>> print({loc: get_display_name(loc) for loc in locales})
{'ar_dz': 'Arabic (Algeria)', 'ar_lb': 'Arabic (Lebanon)', 'ar_ly': 'Arabic (Libya)', 'ar_ma': 'Arabic (Morocco)', 'ar_tn': 'Arabic (Tunisia)', 'ast_es': 'Asturian (Spain)', 'az': 'Azerbaijani', 'az_az': 'Azerbaijani (Latin, Azerbaijan)', 'az_az.iso88599e': 'Azerbaijani (Latin, Azerbaijan)', 'bs': 'Bosnian', 'bs_ba': 'Bosnian (Latin, Bosnia & Herzegovina)', 'ca': 'Catalan', 'ca_ad': 'Catalan (Andorra)', 'ca_es': 'Catalan (Spain)', 'ca_es@valencia': 'Catalan (Spain)', 'ca_fr': 'Catalan (France)', 'ca_it': 'Catalan (Italy)', 'da': 'Danish', 'da_dk': 'Danish (Denmark)', 'de': 'German', 'de_at': 'German (Austria)', 'de_be': 'German (Belgium)', 'de_de': 'German (Germany)', 'de_lu': 'German (Luxembourg)', 'el': 'Greek', 'el_cy': 'Greek (Cyprus)', 'el_gr': 'Greek (Greece)', 'el_gr@euro': 'Greek (Greece)', 'en_be': 'English (Belgium)', 'en_dk': 'English (Denmark)', 'es': 'Spanish', 'es_ar': 'Spanish (Argentina)', 'es_bo': 'Spanish (Bolivia)', 'es_cl': 'Spanish (Chile)', 'es_co': 'Spanish (Colombia)', 'es_ec': 'Spanish (Ecuador)', 'es_es': 'Spanish (Spain)', 'es_py': 'Spanish (Paraguay)', 'es_uy': 'Spanish (Uruguay)', 'es_ve': 'Spanish (Venezuela)', 'eu': 'Basque', 'eu_es': 'Basque (Spain)', 'fo': 'Faroese', 'fo_fo': 'Faroese (Faroe Islands)', 'fr_lu': 'French (Luxembourg)', 'fy_nl': 'Western Frisian (Netherlands)', 'ger_de': 'German (Germany)', 'gl': 'Galician', 'gl_es': 'Galician (Spain)', 'hr': 'Croatian', 'hr_hr': 'Croatian (Croatia)', 'hsb_de': 'Upper Sorbian (Germany)', 'id': 'Indonesian', 'id_id': 'Indonesian (Indonesia)', 'in': 'Indonesian (Indonesia)', 'in_id': 'Indonesian (Indonesia)', 'is': 'Icelandic', 'is_is': 'Icelandic (Iceland)', 'it': 'Italian', 'it_it': 'Italian (Italy)', 'kl': 'Kalaallisut', 'kl_gl': 'Kalaallisut (Greenland)', 'km_kh': 'Khmer (Cambodia)', 'lb_lu': 'Luxembourgish (Luxembourg)', 'lo': 'Lao', 'lo_la': 'Lao (Laos)', 'lo_la.cp1133': 'Lao (Laos)', 'lo_la.ibmcp1133': 'Lao (Laos)', 'lo_la.mulelao1': 'Lao (Laos)', 'mk': 'Macedonian', 'mk_mk': 'Macedonian (Macedonia)', 'nl': 'Dutch', 'nl_aw': 'Dutch (Aruba)', 'nl_be': 'Dutch (Belgium)', 'nl_nl': 'Dutch (Netherlands)', 'ps_af': 'Pashto (Afghanistan)', 'pt': 'Portuguese', 'pt_br': 'Portuguese (Brazil)', 'ro': 'Romanian', 'ro_ro': 'Romanian (Romania)', 'rw': 'Kinyarwanda', 'rw_rw': 'Kinyarwanda (Rwanda)', 'sl': 'Slovenian', 'sl_si': 'Slovenian (Slovenia)', 'sr': 'Serbian', 'sr@cyrillic': 'Serbian', 'sr@latn': 'Serbian', 'sr_cs': 'Serbian (Cyrillic, Serbia)', 'sr_cs.iso88592@latn': 'Serbian (Cyrillic, Serbia)', 'sr_cs@latn': 'Serbian (Cyrillic, Serbia)', 'sr_me': 'Serbian (Latin, Montenegro)', 'sr_rs': 'Serbian (Cyrillic, Serbia)', 'sr_rs@latn': 'Serbian (Cyrillic, Serbia)', 'sr_yu': 'Serbian (Cyrillic, Serbia)', 'sr_yu.cp1251@cyrillic': 'Serbian (Cyrillic, Serbia)', 'sr_yu.iso88592': 'Serbian (Cyrillic, Serbia)', 'sr_yu.iso88595': 'Serbian (Cyrillic, Serbia)', 'sr_yu.iso88595@cyrillic': 'Serbian (Cyrillic, Serbia)', 'sr_yu.microsoftcp1251@cyrillic': 'Serbian (Cyrillic, Serbia)', 'sr_yu.utf8': 'Serbian (Cyrillic, Serbia)', 'sr_yu.utf8@cyrillic': 'Serbian (Cyrillic, Serbia)', 'sr_yu@cyrillic': 'Serbian (Cyrillic, Serbia)', 'tr': 'Turkish', 'tr_cy': 'Turkish (Cyprus)', 'tr_tr': 'Turkish (Turkey)', 'vi': 'Vietnamese', 'vi_vn': 'Vietnamese (Vietnam)', 'vi_vn.tcvn': 'Vietnamese (Vietnam)', 'vi_vn.tcvn5712': 'Vietnamese (Vietnam)', 'vi_vn.viscii': 'Vietnamese (Vietnam)', 'vi_vn.viscii111': 'Vietnamese (Vietnam)', 'wo_sn': 'Wolof (Senegal)'}

Try it online!

Answer 3

有件事，用巴别塔，对我有用。在

首先，您向它提供一些测试数据和您的期望值，然后它将构建一个分隔符字典，以匹配区域设置别名。在

然后你可以从那一点开始转换。在

import string
from decimal import Decimal
from babel.numbers import parse_decimal, NumberFormatError
from babel.core import UnknownLocaleError
import locale

traindata = [
    ("1.234.345,00", Decimal("1234345.00")),
    ("1,234,345.00", Decimal("1234345.00")),
    ("345", Decimal("345.00")),
]

data = traindata + [
    ("345,00", Decimal("345.00")),
    ("345.00", Decimal("345.00")),
    ("746", Decimal("746.00")),
]

def findseps(input_):
    #you need to have no separator 
    #or at least a decimal separator for this to work...

    seps = [c for c in input_ if not c in string.digits]
    if not seps:
        return ""

    sep = seps[-1]
    #if the decimal is something then thousand will be the other...
    seps = "." + sep if sep == "," else "," + sep
    return seps 


def setup(input_, exp, lookup):


    key = findseps(input_)

    if key in lookup:
        return

    for alias in locale.locale_alias:
        #print(alias)

        try:
            got = parse_decimal(input_, locale=alias)
        except (NumberFormatError,UnknownLocaleError, ValueError) as e:
            continue
        except (Exception,) as e:
            raise
        if exp == got:
            lookup[key] = alias
            return


def convert(input_, lookup):
    seps = findseps(input_)
    try:
        locale_ = lookup[seps]
        convert.locale_ = locale_
    except (KeyError,) as e:
        convert.locale_ = None
        return "unexpected seps:%s" % seps

    try:
        return parse_decimal(input_, locale=locale_)
    except (Exception,) as e:
        return e


lookup = {}

#train your data
for input_, exp in traindata:
    setup(input_, exp, lookup)

#once it's trained you know which locales to use
print(data)


for input_, exp in data:
    got = convert(input_, lookup)

    # print (input_)
    msg = "%s => %s with local:%s:" % (input_, got, convert.locale_)
    if exp == got:
        print("\n  success : " + msg)
    else:
        print("\n  failure : " + msg)

print(lookup)

输出：

^{pr2}$