Save changes from Python API

[alexprengere]

Idea

From the Python API, be able to save changes made with set, in the initial loaded file (if any).

Example for a normal base

from GeoBases import GeoBase

g = GeoBase('ori_por', verbose=False)
g.set('ORY', name='Orly')
g.set('new_por', name='new_name')

g.save()

This way the ori_por file would be updated with the new ORY name, and would have a new line for the entry new_por.

Example for a base without initial file

The mechanism can be a bit tricky for bases without regular initial file like feed, so we should be able to do something like this, where we explicitely define everything:

from GeoBases import GeoBase

g = GeoBase('feed')
g.set('key', name='name')

g.save(path='file.csv', headers=['name'])

Since g.fields are not automatically updated when data is set, this may be a good opportunity to use g.syncFields() to synchronise g.fields with the underlying data. If we resume he previous example:

g.fields # []
g.syncFields()
g.fields # ['__dup__', '__gar__', '__key__', '__lno__', '__par__', 'name']

# You may want to remove the __special__ fields
g.save(path='file.csv', headers=g.fields)

Conclusion

I implemented a draft of this specification in the develop branch. Comments/ideas are welcome!

[da115115]

That sounds a very good idea :)

Please, do not forget that ori_por is a generated file. Hence, the modifications will be lost at the next update from OpenTravelData.

I would suggest, in a first easy step, just to create a patch file, which would then be sent by mail, and/or attached to an automatically created issue. Indeed, Geonames does not allow updates through its Web Services (WS), which would have been very convenient otherwise...

[alexprengere]

With 5f031638d67eb56daaad1b9cce58fb012cfafcd1, this works fine with delimited fields. This means that if you change the value of a delimited field (a tuple), then save the results, the file will be updated. Sub-delimiters should be consistent with those used during data loading.

Note that if you modify a raw version of a delimited field, like tvl_por_list@raw, changes will not be saved, since these fields are not dumped by default.