Thanks for the feedback. Vincent Davis 720-301-3003
On Mon, Mar 24, 2014 at 1:44 PM, Chris Angelico <ros...@gmail.com> wrote: > On Tue, Mar 25, 2014 at 4:50 AM, Vincent Davis <vinc...@vincentdavis.net> > wrote: > > I have several csv file I need to append (vertically). They have > different > > but overlapping headers. For example; > > file1 headers ['a', 'b', 'c'] > > file2 headers ['d', 'e'] > > file3 headers ['c', 'd'] > > > > Is there a better way than this > > Summary of your code: > > 1) Build up a set of all headers used, by opening each file and > reading the headers. > 2) Go through each file a second time and write them out. > > That seems like the best approach, broadly. You might be able to > improve it a bit (it might be tidier to open each file once, but since > you're using two different CSV readers, it'd probably not be), but by > and large, I'd say you have the right technique. Your processing time > here is going to be dominated by the actual work of copying. > > The only thing you might want to consider is order. The headers all > have a set order to them, and it'd make sense to have the output come > out as ['a', 'b', 'c', 'd', 'e'] - the first three from the first > file, then adding in everything from subsequent files in the order > they were found. Could be done easily enough by using 'in' and > .append() on a list, rather than using a set. But if that doesn't > matter to you, or if something simple like "sort the headers > alphabetically" will do, then I think you basically have what you > want. > > ChrisA > -- > https://mail.python.org/mailman/listinfo/python-list >
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