Poetry

Using Poetry#

The easiest method for developing PBM is to use the tool poetry which combines handling of python dependencies, virtual environment, deployment and versioning.

Installing PBM with Poetry#

Poetry can be installed using pip:

pip install --user poetry

you can now install the development version of PBM by running:

poetry install

within the repository directory. This will create a virtual environment containing all Python modules required to run the project as defined within the pyproject.toml file.

Any changes made within the repository will be picked up by poetry whenever the code is run.

Running PBM with Poetry#

There are two ways in which you can run the included powerbalance command. Either open a new shall within the created virtual environment:

poetry shell

then run:

powerbalance

or if you do not wish to leave the current shell prefix any command you want to run within the virtual environment with poetry run:

poetry run powerbalance

Troubleshooting#

If you encounter issues with numpy as a dependency, this can usually fixed by installing it manually beforehand:
```
poetry run pip install numpy
```
Another problem encountered on Windows systems is with the installation of PyTables, the error usually states that HDF5 libraries could not be located and is due to there being no built wheels in the PyPi database for the user's Python version and system architecture (when this is the case Python attempts to build the module itself). A working solution is to download the relevant pytables wheels for Windows from here, then install them with pip:
```
poetry run pip install <path-to-wheels-file>
```
If you are using Poetry and the command poetry is not recognised after it has been installed, make sure the location of your poetry installation is added to PATH, to find the installation try running
```
python -m poetry shell
```
and noting the address given during the initialisation. For example for the case of a prefix of C:\Users\<user>\AppData\Local\pypoetry, poetry was found in C:\Users\<user>\AppData\Local\Packages\PythonSoftwareFoundation.<python_version_string>\LocalCache\local-packages\Python<version-num>\Scripts. This location is then added to the PATH variable as described here or temporarily

In the case of Windows:
```
set "PATH=%PATH%;<location-of-poetry.exe>"
```
for Linux/macOS:
```
export PATH=<location-of-poetry>:$PATH
```
If the command powerbalance is not available after install, you can also run the program via Python as normal:
```
python <path-to-cloned-repo>/power_balance/cli/__init__.py
```