PythonPackage parse from string++

[dpgraham4401]

howdy, (retry)

closes #199

The scope of this pull request got a little bigger than I intended it to, and the PythonPackage was pretty much completely re-implemented. While all test are passing on my end, if this causes problems or just simply isn't what you envisioned, don't feel bad about saying so.

here's what we got in this puppy...

1. Implement PythonPackage.op as a new enum (VersionOp)
2. New enum VersionOp
3. PythonPackage private "string" field is replaced by all aspects of the struct field (the string field is gone)
4. The following trait implementation
   • VersionOp
     • Default
     • std::str::FromStr
     • fmt::Display
   • PythonPackage
     • fmt::Display
     • re-implement ::from method so let foo PythonPackage::from("requests==2.28.1".to_string()); parses the python package/dependency from the string.
5. Documentation for many pub structs and functions
6. New test and some todo/placeholder tests

just realize I didn't re-implement PythonPackage's string function, it returns the name currently. we can fix that though.

Like i said, it's a lot so if you have questions or it's just outright in conflict with future plans, just let me know.

I would not consider myself a "rustacean" so there may be plenty of way to improve/make more idiomatic.

[cnpryer]

Honestly I love it. LGTM. If you don't have any other comments I think we can merge. The only thing I'm not 100% on is the extern crate piece in lib.rs.

[cnpryer]

Tag #128

[dpgraham4401]

Cool, looks more idiomatic, this is a learning experience for me.

[cnpryer]

Cool, looks more idiomatic, this is a learning experience for me.

Same 😅. I really like it though so far.