Group "from" and "import" lines for the same module

[bukzor]

Input:

import array
import os
import re

from datetime import datetime
from os.path import join
from zipfile import ZipFile

Current output:

import array
import os
import re
from datetime import datetime
from os.path import join
from zipfile import ZipFile

Desired output:

import array
from datetime import datetime
import os
from os.path import join
import re
from zipfile import ZipFile

This gives a concrete advantage:

• All references to a particular package are in a single, specific place, regardless of import style.

This makes working with the code slightly easier: When refactoring, finding all imports of a package requires just one alphabetical search. When reviewing patches, changes to a particular package will be confined to a single diff-block, even if the import style changes.

There's prior art in the openstack style guide. Most other style guides are either ambiguous or completely unspecified on this fine point. What's more, the "Desired" block passes one of the pylint checks, while the "Current" doesn't.

Most importantly though, this accords with my intuition. I feel it has the same driving force as our trailing-comma policy; among essentially-equal formattings, pick the one that provides the lowest barrier to refactoring.

I'll implement the change if we can agree on the policy.

[asottile]

That's not how it is specced here. If you want to introduce a non default option which enables this feel free to open a pull request

[bukzor]

The request is to agree on an updated spec...