Marking translatable strings

[Barry A. Warsaw]

>>>>> "D" == Darrell  <news at dorb.com> writes:

    D> Wish there was a dictionary formatter that wouldn't throw a
    D> keyError when it was missing a value.

A while back I posted what we use in Mailman:

-------------------- snip snip --------------------
from UserDict import UserDict
from types import StringType

class SafeDict(UserDict):
    """Dictionary which returns a default value for unknown keys.
    """
    def __init__(self, d):
        # optional initial dictionary is a Python 1.5.2-ism.  Do it this way
        # for portability
        UserDict.__init__(self)
        self.update(d)

    def __getitem__(self, key):
        try:
            return self.data[key]
        except KeyError:
            if type(key) == StringType:
                return '%('+key+')s'
            else:
                return '<Missing key: %s>' % `key`
-------------------- snip snip --------------------

>>> 'Well %(hello)s there %(name)s' % sd
'Well howdy there %(name)s'

Hope that helps,
-Barry