How do I strftime a date object in a different loc

问题:

I have a date object in python and I need to generate a time stamp in the C locale for a legacy system, using the %a (weekday) and %b (month) codes. However I do not wish to change the application's locale, since other parts need to respect the user's current locale. Is there a way to call strftime() with a certain locale?

回答1:

The example given by Rob is great, but isn't threadsafe. Here's a version that works with threads:

import locale
import threading

from datetime import datetime
from contextlib import contextmanager


LOCALE_LOCK = threading.Lock()

@contextmanager
def setlocale(name):
    with LOCALE_LOCK:
        saved = locale.setlocale(locale.LC_ALL)
        try:
            yield locale.setlocale(locale.LC_ALL, name)
        finally:
            locale.setlocale(locale.LC_ALL, saved)

# Let's set a non-US locale
locale.setlocale(locale.LC_ALL, 'de_DE.UTF-8')

# Example to write a formatted English date
with setlocale('C'):
    print(datetime.now().strftime('%a, %b')) # e.g. => "Thu, Jun"

# Example to read a formatted English date
with setlocale('C'):
    mydate = datetime.strptime('Thu, Jun', '%a, %b')

It creates a threadsafe context manager using a global lock and allows you to have multiple threads running locale-dependent code by using the LOCALE_LOCK. It also handles exceptions from the yield statement to ensure the original locale is always restored.

回答2:

No, there is no way to call strftime() with a specific locale.

Assuming that your app is not multi-threaded, save and restore the existing locale, and set your locale to 'C' when you invoke strftime.

#! /usr/bin/python3
import time
import locale


def get_c_locale_abbrev():
  lc = locale.setlocale(locale.LC_TIME)
  try:
    locale.setlocale(locale.LC_TIME, "C")
    return time.strftime("%a-%b")
  finally:
    locale.setlocale(locale.LC_TIME, lc)

# Let's suppose that we're french
locale.setlocale(locale.LC_ALL, 'fr_FR.utf8')

# Should print french, english, then french
print(time.strftime('%a-%b'))
print(get_c_locale_abbrev())
print(time.strftime('%a-%b'))

---

If you prefer with: to try:-finally:, you could whip up a context manager:

#! /usr/bin/python3
import time
import locale
import contextlib

@contextlib.contextmanager
def setlocale(*args, **kw):
  saved = locale.setlocale(locale.LC_ALL)
  yield locale.setlocale(*args, **kw)
  locale.setlocale(locale.LC_ALL, saved)

def get_c_locale_abbrev():
  with setlocale(locale.LC_TIME, "C"):
    return time.strftime("%a-%b")

# Let's suppose that we're french
locale.setlocale(locale.LC_ALL, 'fr_FR.utf8')

# Should print french, english, then french
print(time.strftime('%a-%b'))
print(get_c_locale_abbrev())
print(time.strftime('%a-%b'))

回答3:

take a look to the pytz package

you can use like this

import pytz
UTC = pytz.timezone('UTC') # utc
fr = pytz.timezone('Europe/Paris') #your local
from datetime import datetime
date = datetime.now(fr)
dateUTC = date.astimezone(UTC)

strftime will render in the timezone specified

for have month name in the locale use calendar for example :

import calendar
print calendar.month_name[dateUTC.month] #will print in the locale

inspect more deeply calendar for having more information