-r optional.txt

flake8==3.8.4
flake8-breakpoint==1.1.0
flake8-isort==4.0.0
flake8-mutable==1.2.0
flake8-no-u-prefixed-strings==0.2
flake8-polyfill==1.0.2
isort==5.6.4
pre-commit==2.8.2
pycodestyle==2.6.0
pydocstyle==5.1.1
pytest==6.1.2
pytest-cov==2.10.1
pytest-xdist==2.1.0
Sphinx==3.3.0
twine==3.2.0
virtualenv==20.1.0
