Polywrap is a developer tool that enables easy integration of Web3 protocols into any application. It makes it possible for applications on any platform, written in any language, to read and write data to Web3 protocols.

This MVP Python client enables the execution of WebAssembly Polywrappers (or just "wrappers") on a python environment, regardless of what language this wrapper was built in.

The client is built following the functionality of the JavaScript Polywrap Client, which is currently more robust and battle tested, as it has additional capabilities than this MVP. In the future, the Polywrap DAO will continue improving this Python capabilities to reach feature parity with the JS stack, while building in parallel clients for other languages like Go and Rust.

Here you can see which features have been implemented on each language, and make the decision of which one to use for your project.

Have questions or want to get involved? Join our community Discord or open an issue on Github.

For detailed information about Polywrap and the WRAP standard, visit our developer documentation.

git clone https://github.com/polywrap/python-client

• Make sure you're running the correct version of python by running:

python3 --version

If you are using a Linux system or WSL, which comes with Python3.8, then you will need to upgrade from Python3.8 to Python3.10 and also fix the pip and distutil as upgrading to Python3.10 will break them. You may follow this guide to upgrade.

• To install poetry follow this guide.
• If you are on MacOS then you can install poetry simply with the following homebrew command

brew install poetry

To make sure you're it's installed properly, run poetry. Learn more here

• We will be using Poetry for building and testing our packages. Each of the package folders consists of the pyproject.toml file and the poetry.lock file. In pyproject.toml file, one can find out all the project dependencies and configs related to the package. These files will be utilized by Poetry to install correct dependencies, build, lint and test the package.

• For example, we can install deps, build and test the polywrap-msgpack package using Poetry.

• Install dependencies using Poetry.

poetry install

Make sure your cwd is the appropriate module, for example polywrap-msgpack, polywrap-wasm or polywrap-client.

In order to assure the integrity of the modules Polywrap Python Client uses pytest 7.1.3 as a testing framework.

• As we can see in the pyproject.toml files, we installed the PyTest package. We will be using it as our testing framework.
• Now we are ready to build and test the core package using Poetry and PyTest.

To build the package run the following command

poetry build

You need to activate the venv with poetry using the shell command before running any other command

poetry shell

Finally, to test your module to execute the test suite:

poetry run pytest

This last command will run a series of scripts that verify that the specific module of the client is performing as expected in your local machine. The output on your console should look something like this:

$ poetry run pytest
>>
================================= test session starts =================================
platform darwin -- Python 3.10.0, pytest-7.1.3, pluggy-1.0.0
rootdir: /Users/polywrap/pycode/polywrap/toolchain/packages/py, configfile: pytest.ini
collected 26 items                                                                    

tests/test_msgpack.py ........................                                  [100%]

You should expect to see the tests passing with a 100% accuracy. To better understand these outputs, read this quick guide. If any of the functionality fails (marked with an 'F'), or if there are any Warnings raised, you can debug them by running a verbose version of the test suite:

• poetry run pytests -v or poetry run pytests -vv for even more detail
• Reach out to the devs on the Discord explaining your situation, and what configuration you're using on your machine.

We are using tox to run lint and tests even more easily. Below are some basic commands to get you running.

tox -a

tox

tox -e lint

tox -e typecheck

tox -e secure

Use this command to only apply lint fixes and style formatting.

tox -e dev

• After running these commands we should see all the tests passing and commands executing successfully, which means that we are ready to update and test the package.
• To create your own tox scripts, modify the tox.ini file in the respective module.

If you use VSCode, we have prepared a pre-configured workspace that improves your dev experience. So when you open VScode, set up the workspace file python-monorepo.code-workspace by going to:

File -> Open Workspace from File...

Each folder is now a project to VSCode. This action does not change the underlying code, but facilitates the development process. So our file directory should look like this now:

Note: You might have to do this step again next time you close and open VS code!

We will need to create a .vscode/settings.json file in each module's folder, pointing to the in-project virtual environment created by the poetry.

• You can easily find the path to the virtual env by running following command in the package for which you want to find it for:

poetry shell

• Once you get the path virtual env, you need to create the following settings.json file under the .vscode/ folder of the given package. For example, in case of polywrap-client package, it would be under ./polywrap-client/.vscode/settings.json

Here's the structure settings.json file we are using for configuring the vscode. Make sure you update your virtual env path you got from poetry as the python.defaultInterpreterPath argument:

{
  "python.formatting.provider": "black",
  "python.languageServer": "Pylance",
  "python.analysis.typeCheckingMode": "strict",
  "python.defaultInterpreterPath": "/Users/polywrap/Library/Caches/pypoetry/virtualenvs/polywrap-client-abcdef-py3.10"
}

Keep in mind that these venv paths will vary for each module you run poetry shell on. Once you configure these setting.json files correctly on each module you should be good to go!

Check these resources to browse a variety available wrappers, for DeFi, decentralised storage, and other development utilites:

• Wrappers.io
• Polywrap Integrations Repository

Calling a function of a wrapper from the python client is as simple as creating a file in the TODO (?polywrap-client) directory, importing the PolywrapClient, calling the Uri where the WASM wrapper is hosted, and specifying any required arguments.

Here is an example which takes in a message as a string and returns it.

# hello_world.py
from polywrap_client import PolywrapClient
from polywrap_core import Uri, InvokerOptions

async def echo_message(message: str):
    
    # Instantiate the client
    client = PolywrapClient()
    
    # Load the WebAssembly wrapper through a URI that points to local file system
    uri = Uri('wrap://ens/rinkeby/helloworld.dev.polywrap.eth')

    args = {"arg": message }

    # Configure the client
    options = InvokerOptions(
        uri=uri, method="simpleMethod", args=args, encode_result=False
    )
    
    # Invoke the wrapper 
    result = await client.invoke(options)

    return result.result

if __name__ == "__main__":
    return echo_message('hello polywrap!')

By creating tests you can quickly experiment with the Polywrap Client and its growing set of wrappers. Since Pytest is already set up on the repo, go to the polywrap-client\tests\ directory, and take a look at how some of the functions are built. You can use similar patterns to mod your own apps and build new prototypes with more complex functionality.

Here's a good guide to learn about building tests with Pytest

The Polywrap project is completely open-source and we welcome contributors of all levels. Learn more about how you can contribute here.

Join our discord and ask your questions right away!

• Polywrap Documentation
• Polywrap Integrations Repository
• Running operations concurrently with python's asyncio
• Intro Video