### 21.1.3.4 Deferred translations

In most coding situations, strings are translated where they are coded. Occasionally however, you need to mark strings for translation, but defer actual translation until later. A classic example is:

    animals = ['mollusk',
               'albatross',
    	   'rat',
    	   'penguin',
    	   'python',
    	   ]
    # ...
    for a in animals:
        print a

Here, you want to mark the strings in the `animals` list as being translatable, but you don't actually want to translate them until they are printed.

Here is one way you can handle this situation:

    def _(message): return message

    animals = [_('mollusk'),
               _('albatross'),
    	   _('rat'),
    	   _('penguin'),
    	   _('python'),
    	   ]

    del _

    # ...
    for a in animals:
        print _(a)

This works because the dummy definition of `_()` simply returns the string unchanged. And this dummy definition will temporarily override any definition of `_()` in the built-in namespace (until the `del` command). Take care, though if you have a previous definition of `_` in the local namespace.

Note that the second use of `_()` will not identify ``a'' as being translatable to the pygettext program, since it is not a string.

Another way to handle this is with the following example:

    def N_(message): return message

    animals = [N_('mollusk'),
               N_('albatross'),
    	   N_('rat'),
    	   N_('penguin'),
    	   N_('python'),
    	   ]

    # ...
    for a in animals:
        print _(a)

In this case, you are marking translatable strings with the function `N_()`,21.5 which won't conflict with any definition of `_()`. However, you will need to teach your message extraction program to look for translatable strings marked with `N_()`. pygettext and xpot both support this through the use of command line switches.

#### Footnotes

...N_(),21.5
  The choice of `N_()` here is totally arbitrary; it could have just as easily been `MarkThisStringForTranslation()`.