src layoutでのsetup.cfg

One commonly used package configuration has all the module source code in a subdirectory (often called the src/ layout),

# This example contains just the necessary options for a src-layout, set up the rest of the file as described above.

code:src_layout_example.cfg

package_dir=

=src

packages=find:

where=src

where=srcだけでよくなる

tests以下をexcludeする必要がない（testsはsrcと同じ階層）

参考