drunkwcodes

Can we add a convention like [this?](https://github.com/rust-lang/cargo/wiki/Third-party-cargo-subcommands) This needs to handle args mismatch like [this](https://github.com/rust-lang/cargo/blob/d74d879d63c0be7cd87a29fd23229b58dfceb754/src/bin/cargo/cli.rs#L12) and allows us to create subcommands in other projects.

At the mean time I found this: https://poetry.eustace.io/docs/plugins/#creating-a-plugin

There is a Rust implementation of CSS Syntax Level 3. https://github.com/servo/rust-cssparser

This PR may really break python2.7 compatibility in `master` such as string prefix u deletion. Would you like to add a warning for python2 users pinning the version to 5?...

@alok Fine. But [PEP461 formatting?](https://www.python.org/dev/peps/pep-0461/)

@alok That is the proof of unnecessity about the change of string formatting. Reverting those changes and `u` prefix deletion makes this PR less possible to be rejected.

@energizerhub `-r` will be only familiar to you.

I use black quite smoothly lately. Seldom problems. And the trailing comma switch is effective. This feature is still not significant at the first glance, and should be promoted more....

The `max_retries=6` (secs) without feedbacks is too long for a failed command to me. Please add a error message above the `sleep(1)`

Would you like to use this method to find out which program kept the files? https://youtu.be/PDab6s7cWqk P.S If this issue keeps you from trying poetry, it will keeps you from...