bpo-43322: Use consistent '#include' syntax in extn. tutorial

[matthewhughes934]

Use the same format for Python header files

https://bugs.python.org/issue43322

[Blackpower1972]

https://github.com/python/cpython/pull/24820vstinner:urllib_basic_auth_regexLib/urllib/request the192.168.1.1/32https://github.com/python/cpython/pull/18284#issue-369132952[export http_proxy=http://alice.example.com:8080](https://github.com/python/cpython/pull/24838)

[Blackpower1972]

vstinner:urllib_basic_auth_regexLib/urllib/request.pyvstinner:urllib_basic_auth_regexexport http_proxy=http://alice.example.com:8080JunyiXie:fix/pymalloc_subinterpretervstinner:urllib_basic_auth_regexexport http_proxy=http://alice.example.com:8080

[github-actions]

This PR is stale because it has been open for 30 days with no activity.

[iritkatriel]

There is a difference in C between these two formats. Are you suggesting this just for consistency or because you think the example is currently incorrect?

[matthewhughes934]

There is a difference in C between these two formats. Are you suggesting this just for consistency or because you think the example is currently incorrect?

Purely for consistency. From what I understand the quotes will perform an implementation defined search then fallback to the (implementation defined) search method used by <> and I think in this case the distinction shouldn't be significant.

I think in general this looks something like "" searches around the source file with the #include directive and <> checks across some system paths, in this context I think the <> is more appropriate here, since I assume we're wanting users to build against the system CPython library, rather then e.g. cloning the repository and building there. But that's all implementation defined and I'm not sure how many compilers actually behave like that.