Download files from Data Portal

[glourencoffee]

Description

As a library user, I want to download files from CVM's Data Portal using this library.

Challenge

Having to download a CVM file to my filesystem and find it when I only care about using it with this library. Moreover, I have to know the URL of CVM's Data Portal where I can download the files, when this library could just tell me.

Benefit

Abstraction

Acceptance criteria

• A file whose type is a member of DocumentType can be downloaded from the Data Portal
• User can specify the year of the file to be downloaded
• Error is raised if no file is found in the Data Portal for a given year

Additional context

Here is how the feature could look like:

>>> import cvm
>>> cvm.download_url()
'https://dados.cvm.gov.br/'
>>> response = cvm.download(cvm.DocumentType.DFP, 2010)