Thanks Mr.Khalil! I will surely give it a try! On 30 April 2012 13:24, Khalil KHAMLICHI <[email protected]> wrote:
> Raul, when working with the web you always (most of the times) create the > files server side and invite user to download it and save it to his file > system, this sais you don't need to access the file system yourself, just > invite the user to download your file and you are done. > for csv versus txt files, they are both the same thing IF the user is not > going to import them into some other software that needs only csv content, > python has a module called StringIO, you can use it as a file and write to > it mixed content : simple text and csv data. > > On Mon, Apr 30, 2012 at 6:03 AM, RAHUL PRIYADARSI > <[email protected]>wrote: > >> Dear All, >> Thanks for your answers.But what I was looking for was,putting into >> simple words,implementing a use case similar to the following "The system >> maintains the data related to each transaction.Each transaction includes >> the list of items demanded per transaction with each item belonging to a >> category.The system also generates an aggregated report per transaction as >> well as an overall report of the total items belonging to each category >> demanded.".Now "the report" here need not be in csv only.It may be txt >> file.Since I am not sure as to whether is it possible to print formatted >> strings(e.g. the string "report" printed right aligned in a total field of >> 15 characters,something likd printf(%15s)) in web2py,my question is that >> how we do file IO in web2py. Can we generate a txt file in web2py. And can >> we print formatted strings to it? >> Since the controller runs on server and my application would be deployed >> in an intranet lan and it needs to generate files to be used in local file >> system of the system on which the user will access the app , where must >> this file IO code be written, in controller or view. >> >> >> On 30 April 2012 07:35, Brian M <[email protected]> wrote: >> >>> Yep, I've got a processing app that spits out all sorts of csv files >>> based on data gathered from multiple sources. >>> >>> Here's a little helper function I use >>> >>> def csv_export(records, column_names, fields, mode = 'dal'): >>> """Export DAL result set, list of dicts or list of lists to CSV >>> stream for returning to user >>> Arguments: >>> records = the data to be returned >>> column_names (list)= the column names/headings for the first row in >>> the CSV file >>> Example ['First Name', 'Last Name', 'Email'] >>> fields (list) = the names of the fields (as they appear in records) >>> in the order they >>> should be in the CSV. Example ['f_name', 'l_name', >>> 'email'] >>> or ['table_a.f_name', 'table_a.l_name', >>> 'table_b.email'] >>> If mode = 'list' and your records are in the correct >>> order then fields may be None >>> otherwise use [1,3,0] if you list is in a different >>> order >>> mode (string) = what type of data is in records? 'dal' (Default), >>> 'dict' or 'list' >>> 'dal' if records came from a regular dal query >>> (Default) >>> 'dict' if records are a list of dicts (for example >>> using db.executesql() with as_dict = True) >>> 'list' if records are a list of lists/tuples (for >>> example using db.executesql() with as_dict = False) >>> >>> """ >>> >>> #create fake file object >>> import cStringIO >>> file = cStringIO.StringIO() >>> #setup csv writer >>> import csv >>> csv_file = csv.writer(file) >>> #write first row withspecified column headings/names >>> csv_file.writerow(column_names) >>> #which mode - dal or dict? >>> if mode.lower() == 'dal' or mode.lower() == 'dict': >>> for record in records: >>> csv_file.writerow([record[field] for field in fields]) >>> elif mode.lower() == 'list': >>> if fields == None: >>> csv_file.writerows(records) >>> else: >>> for record in records: >>> csv_file.writerow([record[field] for field in fields]) >>> return file >>> >>> >>> >>> Then in a controller you can have something like >>> >>> csv_stream = csv_export(processed_dataset, column_names, fields, >>> mode = 'dict') >>> response.headers['Content-Type']='application/vnd.ms-excel' >>> response.headers['Content-Disposition']='attachment; >>> filename=data_for_%s.csv' % date.today() >>> return csv_stream.getvalue() >>> >>> which will cause browser to download the csv file with your chosen >>> filename >>> >>> you could also turn around and save the datafile to the filesystem if >>> you wanted. >>> >>> Hope this helps! >>> Brian >>> >>> >>> On Saturday, April 28, 2012 5:20:15 AM UTC-5, rahulserver wrote: >>>> >>>> I wish to generate a few reports in csv or txt or other file formats >>>> based on some database data maintained through a crud application. >>>> Previously, it was done through an asp.net application with vb as >>>> scripting language.But as I explored the wonderful capabilities of web2py, >>>> I have become a fan of this terrific framework. >>>> Is it possible to do it in web2py. And if it is, then how and where >>>> should the code be placed.In the view or model or controller? >>>> >>> >> >
