Joe Strout wrote:
Catching up on what's new in Python since I last used it a decade ago,
I've just been reading up on template strings. These are pretty cool!
However, just as a template string has some advantages over %
substitution for building a string, it seems like it would have
advantages over manually constructing a regex for string matching.
So... is there any way to use a template string for matching? I
expected something like:
.......
you could use something like this to record the lookups
>>> class XDict(dict):
... def __new__(cls,*args,**kwds):
... self = dict.__new__(cls,*args,**kwds)
... self.__record = set()
... return self
... def _record_clear(self):
... self.__record.clear()
... def __getitem__(self,k):
... v = dict.__getitem__(self,k)
... self.__record.add(k)
... return v
... def _record(self):
... return self.__record
...
>>> x=XDict()
>>> x._record()
set([])
>>> x=XDict(a=1,b=2,c=3)
>>> x
{'a': 1, 'c': 3, 'b': 2}
>>> '%(a)s %(c)s' % x
'1 3'
>>> x._record()
set(['a', 'c'])
>>>
a slight modification would allow your template match function to work even when
some keys were missing in the dict. That would allow you to see which lookups
failed as well.
--
Robin Becker
--
http://mail.python.org/mailman/listinfo/python-list
