Question

I am trying to make a simple localization module that takes a key name and returns the localized string based on the language given. The language is one of the constants and maps to a python file that contains the string table. I want to do this dynamically at runtime. Below is my approach, but GAE does not support the imp module. Is there an alternative way to do this?

import logging
import imp

import localizable

LANGUAGE_EN = "en"
LANGUAGE_JP = "ja"

class Localizer(object):
    """
    Returns a localized string corresponding to unique keys
    """
    @classmethod
    def localize(cls, language = LANGUAGE_EN, key = None):
        user_language = imp.load_source("localizable.%s" % language, "/")
        if (user_language):
            return user_language.Locale.localize(key)
        else:
            logging.error("Localizable file was not found")
            return ""

I put the language files in localizable/en.py, etc.

Answer 1

The alternative to the imp module that (I believe) should be available in GAE is __import__(). It’s in fact what the ‘import’ statement calls to do the actual importing.

user_language = getattr(__import__('localizable.%s' % language), language)

or

user_language __import__('localizable.%s' % language, {}, globals(), [''])

(passing a non-empty fourth argument to __import__ causes it to return the right-most module in the first argument, instead of the left-most. It’s a little hacky, so people tend to prefer the first solution over the second.)