feat: add a basic async python client starting point (#1014)

This changes `lancedb` from a "pure python" setuptools project to a
maturin project and adds a rust lancedb dependency.

The async python client is extremely minimal (only `connect` and
`Connection.table_names` are supported). The purpose of this PR is to
get the infrastructure in place for building out the rest of the async
client.

Although this is not technically a breaking change (no APIs are
changing) it is still a considerable change in the way the wheels are
built because they now include the native shared library.

python/README.md

@@ -20,10 +20,10 @@ results = table.search([0.1, 0.3]).limit(20).to_list()
 print(results)
 ```
 
-
 ## Development
 
-Create a virtual environment and activate it:
+LanceDb is based on the rust crate `lancedb` and is built with maturin.  In order to build with maturin
+you will either need a conda environment or a virtual environment (venv).
 
 ```bash
 python -m venv venv
@@ -33,7 +33,15 @@ python -m venv venv
 Install the necessary packages:
 
 ```bash
-python -m pip install .
+python -m pip install .[tests,dev]
+```
+
+To build the python package you can use maturin:
+
+```bash
+# This will build the rust bindings and place them in the appropriate place
+# in your venv or conda environment
+matruin develop
 ```
 
 To run the unit tests:
@@ -45,7 +53,7 @@ pytest
 To run the doc tests:
 
 ```bash
-pytest --doctest-modules lancedb
+pytest --doctest-modules python/lancedb
 ```
 
 To run linter and automatically fix all errors:
@@ -61,31 +69,27 @@ If any packages are missing, install them with:
 pip install <PACKAGE_NAME>
 ```
 
-
 ___
 For **Windows** users, there may be errors when installing packages, so these commands may be helpful:
 
 Activate the virtual environment:
+
 ```bash
 . .\venv\Scripts\activate
 ```
 
 You may need to run the installs separately:
+
 ```bash
 pip install -e .[tests]
 pip install -e .[dev]
 ```
 
-
 `tantivy` requires `rust` to be installed, so install it with `conda`, as it doesn't support windows installation:
+
 ```bash
 pip install wheel
 pip install cargo
 conda install rust
 pip install tantivy
 ```
-
-To run the unit tests:
-```bash
-pytest
-```