pylint woes
DFS
nospam at dfs.com
Sun May 8 17:24:09 EDT 2016
On 5/8/2016 7:36 AM, Steven D'Aprano wrote:
> 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?
Because it exists in 2 different sections of the document.
names = tree.xpath('//span[@class="header_text3"]/text()')
addresses = tree.xpath('//span[@class="text3"]/text()')
I thought you were a "master who knew her tools", and I was the
apprentice?
So why did "the master" think xpath() was magic?
> 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.
That's atomicity.
> But I don't know what you mean by it.
http://www.databasedesign-resource.com/atomic-database-values.html
>> so I parse street, city, state, and
>> zip into their own lists.
>
> None of which is atomic.
All of which are 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:])
That's a good one.
Chris Angelico mentioned something like that, too, and I already put it
place.
> Oh, and use better names. "street" is a single street, not a list of
> streets, note plural.
I'll use whatever names I like.
More information about the Python-list
mailing list