Install the Python API¶

Requirements¶

Qiskit must be installed in the same Python environment that you install qiskit-fermions in. The simplest way to do this is from PyPI, but you can install Qiskit from source if you want to.

$ pip install qiskit

Steps¶

Assuming that you have already installed Qiskit into your Python environment (see here), the remaining installation process is fairly simple:

Ensure that you are in the right directory:
```
$ cd path/to/qiskit-fermions
```
Install the Python installation tooling:
```
$ pip install --group build
```
Install the qiskit-fermions Python package into your environment:
```
$ pip install .
```
Hint

You can also perform an editable install while still compiling the underlying Rust crate in release mode:
```
$ SETUPTOOLS_RUST_CARGO_PROFILE=release pip install -e .
```
Hint

Some features rely on optional dependencies. To install all of them, use the all extra:
```
$ pip install ".[all]"
```
Refer to the [project.optional-dependencies] section of pyproject.toml to see which dependency groups are available.
(optional) You may wish to generate the Python type stub files to have better integration with coding tools (e.g. for tab completion). You can do that quite simply like so:
```
$ make pystubs
```
(optional) Verify that the installation was successful: The simplest test is to try and import one of the classes provided by the qiskit-fermions package, for example like so:
```
$ python -c "from qiskit_fermions.circuit import FermionicCircuit"
```
If this completes successfully, your installation worked.
Hint

If you have performed an editable install, you can also run the entire Python test suite:
```
$ pip install --group test
$ make testpython
```
To additionally run the tests that exercise optional dependencies, install the extras and use the testoptional target:
```
$ pip install -e ".[all]"
$ make testoptional
```