# hello

The smallest useful modern CPython extension module.

```bash
python -m pip install -e . --no-build-isolation -v
python -c "import hello; print(hello.greet('Ada'), hello.add_one(41))"
python -m pytest -q
```

Remember: editing `hello.c` requires a rebuild. Re-run the install command.

Things to try:

1. Rename `PyInit_hello` to `PyInit_helo`, rebuild, and read the import error.
2. Remove the `PyErr_Occurred()` check in `add_one` and call `hello.add_one("x")`.
3. Change `METH_FASTCALL` to `METH_VARARGS` on `greet` and see what breaks.
4. Print `sysconfig.get_config_var("EXT_SUFFIX")` and match it against the built file.