All reports of package-installs-python-pycache-dir for the archive. The extended description of this tag is:
The package installs a __pycache__ directory, which is normally only used to store compiled Python source files. Compiled Python source files must not be included in the package, instead they should be generated at installation time in the postinst.
Note this tag is issues even if the directory is empty.
Refer to Debian Python Policy section 3.7 (Modules Byte-Compilation) for details.
This tag has not been emitted in any package tested by Lintian.