Stuck on a three word street name regex

Brian D briandenzer at gmail.com
Thu Jan 28 14:48:48 CET 2010


On Jan 28, 7:40 am, Brian D <brianden... at gmail.com> wrote:
> > > [snip]
> > > Regex doesn't gain you much. I'd split the string and then fix the parts
> > > as necessary:
>
> > >  >>> def parse_address(address):
> > > ...     parts = address.split()
> > > ...     if parts[-2] == "S":
> > > ...         parts[1 : -1] = [parts[-2]] + parts[1 : -2]
> > > ...     parts[1 : -1] = [" ".join(parts[1 : -1])]
> > > ...     return parts
> > > ...
> > >  >>> print parse_address("1000 RAMPART S ST")
> > > ['1000', 'S RAMPART', 'ST']
> > >  >>> print parse_address("100 JOHN CHURCHILL CHASE  ST")
> > > ['100', 'JOHN CHURCHILL CHASE', 'ST']
>
> > This is a nice approach I wouldn't have thought to pursue. I've never
> > seen this referencing of list elements in reverse order with negative
> > values, so that certainly expands my knowledge of Python. Of course,
> > I'd want to check for other directionals -- probably with a list
> > check, e.g.,
>
> > if parts[-2] in ('E', 'W', 'N', 'S'):
>
> > Thanks for sharing your approach.
>
> After studying this again today, I realized the ingeniousness of
> reverse slicing the list (or perhaps right slicing) -- that one
> doesn't have to worry about the number of words in the string.
>
> To translate for those who may follow, the expression "parts[1 : -1]"
> means gather list items from position one in the list (index position
> 2) to one index position before the end of the list. The value in this
> is that we already know the first list element after a split() will be
> the street number. The last element will be the street type.
> Everything in between, no matter how many words, will be the street
> name -- excepting, of course, the instances where there's a street
> direction added in, as captured in example above.
>
> A very nice solution. Thanks again!

Correction:

[snip] the expression "parts[1 : -1]" means gather list items from the
second element in the list (index value 1) to one index position
before the end of the list. [snip]



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