Write mode for topen

Overview

It’s a long shot but eventually I suppose it could be implemented.

Having a task to write some tabular data to the filesystem is casual. With all the boilerplate code to support py2/3, csv verbose interface etc - it’s a little bit annoying.

Analysis

Interface could be:

with topen('table.csv', mode='w') as table:
    table.write(data)

Implementation could be:

• topen returns ReadTable or WriteTable regarding to the mode='r/w'
• for writing there will be new modules like Formatter (anti-parser) and Writer (anti-loader) with the same modular arhictecture for different targets and formats.

So we will be able to have memory lean things like:

with (topen('http://site.com/source.xls') as source, 
      topen('target.csv', mode='w') as target):
    target.write(source)

Or even with something like tcopy helper:

tcopy(data, 'target.csv')
tcopy('http://site.com/source.xls', 'target.csv')

Tasks

• TBD
• We should support recoding - https://github.com/frictionlessdata/tabulator-py/issues/50

[roll]

@pwalsh Just lazy example) We use streams here) So it should be memory lean.

After we will finish it my idea to create example like loading 1GB xls from the web and saving it to csv file with memory profiler showing we don’t use memory)

[pwalsh]

@roll ok, if that is the internal design. In your examples above, would the writing require the file contents to be loaded to memory? The API description looks like yes, but that would be a mistake IMHO.