csv / xls(x) reading for more formats

[JGuetschow]

Is your feature request related to a problem? Please describe.

Currently reading from wide format csv files is implemented (long format under development). However, some datasets use different formats, e.g. a table with gas and category as dimensions where each year has an individual sheet or file.

Describe the solution you'd like

Function that reads csv files from a folder or sheets from an xls(x) file into the interchange format.

Describe alternatives you've considered

Processing using external tools like the primap1 data_converter helper scripts

Additional context

For an example see e.g. the CEADs data for china. www.ceads.net/

[JGuetschow]

Currently working on a set of function to help reading from different xls and csv formats which need custom code.

[JGuetschow]

The current way to tackle data reading is to use custom code to convert to a long or wide pandas DataFrame and then convert that to interchange format. It might not be worth the effort to further generalize the data reading functions as functions that can read from more format can become overly complex in use and might not be preferable over custom code per dataset.

[mikapfl]

Yeah, I'd say let's start with custom code per dataset, and if we notice we are writing the same code over and over, we generalize and include more into primap2.