pylint woes
Steven D'Aprano
steve at pearwood.info
Sun May 8 07:36:25 EDT 2016
On Sun, 8 May 2016 11:16 am, DFS wrote:
> address data is scraped from a website:
>
> names = tree.xpath()
> addr = tree.xpath()
Why are you scraping the data twice?
names = addr = tree.xpath()
or if you prefer the old-fashioned:
names = tree.xpath()
addr = names
but that raises the question, how can you describe the same set of data as
both "names" and "addr[esses]" and have them both be accurate?
> I want to store the data atomically,
I'm not really sure what you mean by "atomically" here. I know what *I* mean
by "atomically", which is to describe an operation which either succeeds
entirely or fails. But I don't know what you mean by it.
> so I parse street, city, state, and
> zip into their own lists.
None of which is atomic.
> "1250 Peachtree Rd, Atlanta, GA 30303
>
> street = [s.split(',')[0] for s in addr]
> city = [c.split(',')[1].strip() for c in addr]
> state = [s[-8:][:2] for s in addr]
> zipcd = [z[-5:] for z in addr]
At this point, instead of iterating over the same list four times, doing the
same thing over and over again, you should do things the old-fashioned way:
streets, cities, states, zipcodes = [], [], [], []
for word in addr:
items = word.split(',')
streets.append(items[0])
cities.append(items[1].strip())
states.append(word[-8:-2])
zipcodes.append(word[-5:])
Oh, and use better names. "street" is a single street, not a list of
streets, note plural.
--
Steven
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