## Deploying our contract to the blockchain We are going to learn how to compile Vyper in a script and deploy it to a blockchain. First, we are going to create a new file called `deploy_favorites.py`. This is going to be our Python file for actually deploying our smart contract to a blockchain. Here is a bit of a Python tip: in Python, whenever you call a file (for example, when we did `python3.11 basic_python.py` from the last course or from the last section, or if we ran `python3.11 hello.py` or even if we did `uv run python hello.py`), we might see a pop up. We will fix our Python environment in just a second; for now, feel free to just hit that X there. But you will see `Hello from web3py-favorites-cu` or whatever you have in your `hello.py`. You will see, actually, UV gave us this weird template: ```python if __name__ == "__main__": main() ``` If `__name__ == "__main__":` this string main calls the main function, which prints this out. Whenever you run a file, you essentially say, "hey, make the name that you are looking to call `__main__`." So typically we like to be very explicit when we are coding in a more professional environment. So we are actually going to follow this same convention in our `deploy_favorites.py`. We are going to close everything here and I am going to paste this line in here: ```python if __name__ == "__main__": main() ``` Now, these double underscores are also known as dunder names or double underscore names. This is called `__name__` and this is called `__main__`, which means double underscore, so, double underscore name and double underscore main. If `__name__ == "__main__":` run main. We will create a little `def main`: ```python def main(): print("Hello from deploy_favorites.py") ``` And to make sure this is working, we can do a little `print`: ```python print("Hello from deploy_favorites.py") ``` And you can see right there, actually, this is my GitHub Copilot giving me a suggestion. And since I want to take it, I'm going to go ahead and hit tab to add it to my file. Then, of course, hit command s or control s to save. And we can get rid of the pass line now. To make sure this is working, we can run: ```bash uv run python deploy_favorites.py ``` and we should get `Hello from deploy_favorites.py`. But, if you get sick of always doing `uv run python`, we can also, once again, do `uv venv`: ```bash uv venv ``` We can then do this line (I'm just going to copy and paste it): ```bash source .venv/bin/activate ``` Now, we have our virtual environment setup. And now we can just run: ```bash python deploy_favorites.py ``` and I can just hit tab to auto complete. And we get a `Hello from deploy_favorites.py`. Great!