Thanks Mike (& Craig) for confirming that iteration of some sort is the way to
It’s interesting that the url container can be addressed directly, instead of
loading the file - I’d not seen that before. I’m currently pulling each file
into a regular variable, so will probably stick with that as only a few
(existing) lines of code would be saved and the net overall effect on timing /
resources is probably marginal if the file gets loaded behind the scenes anyway.
As the column names/numbers vary by CSV file name - which I have built-out in a
ColumnsOfInterest field - it looks like I’ll also be safe to iterate through
these items to build the row extraction line dynamically, too.
Great, thanks again - I have a direction of travel.
> On 20 Sep 2016, at 21:32, Mike Bonner <bonnm...@gmail.com> wrote:
> If a file you can do this..
> repeat for each line tline in url "file:yourfilename.csv"
> put item 1 of tLine & comma & item 3 of tline & comma & item 15 of tLine &
> return after tExtracted
> end repeat
> delete the last char of tExtracted -- remove the extraneous return
> Or you can put them into an array or whatever. It should be VERY fast. If
> the files are very large, you can instead open the file for read, read a
> line, extract the data as above, and repeat till the end of the file. I
> think using repeat for each with a file url loads the whole thing at once
> then goes line to line, but I'm not sure of that.
> On Tue, Sep 20, 2016 at 2:16 PM, Keith Clarke <keith.cla...@me.com> wrote:
>> Hi folks,
>> I’ve a large number of sizeable CSV files from each of which I need to
>> extract just 2 or 3 specific columns. Creating nested iterations through
>> every item in every line seems somewhat inefficient - as does loading each
>> full file into memory - so I feel I must be missing a trick here.
>> Does Livecode support any elegant way of directly manipulating or
>> ‘querying’ (like SQL) delimited data, to extract numbered (or named)
>> columns/items - such as 1(Id), 3(Name) & 15(Summary) - from in each line
>> from a CSV container or direct from a file/URL?
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