Create containers with `mkdir`

[wachsylon]

It would be nice to have the mkdir method at least for the lowest level, the container because it seems container are not created on the fly when a mapper is used. If the container testtzis does not exist in the following account, the mapper runs into an error:

a=fsspec.get_mapper("swift://swift.dkrz.de/dkrz_4236b71e-04df-456b-8a32-5d66641510f2/testtzis/testcmip6")
a[".test"]=b"ho"

404, message='Not Found', url=URL('https://swift.dkrz.de/v1/dkrz_4236b71e-04df-456b-8a32-5d66641510f2/testtzis/testcmip6/.test')

Do you think that is possible?

[d70-t]

Yes, implementing mkdir and rmdir on containers should be straight forward (I'd consider it the second level though, because there are accounts as well. We'd need (from the SWIFT API):

• PUT /v1/{account}/{container} for mkdir
• DELETE /v1/{account}/{container} for rmdir

I'd probably even go one step further (maybe in another PR) and also catch the error you describe. Then create the container and redo the request. We might want to make this optional though...

I might not be able to that change very soon, but PR's are welcome.