Missing typing_extensions dependency

[brentvollebregt]

Eel version

0.18.0

Describe the bug

When installing the latest version of Eel and importing it, it will raise a ModuleNotFoundError.

To Reproduce

1. Get a clean environment (python -m venv .venv and .\.venv\Scripts\Activate.ps1 - or any other method)
2. Install Eel: python -m pip install Eel
3. Open a Python shell: python
4. Import Eel: import eel

You will get the error,

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "WORKING_DIR\.venv\lib\site-packages\eel\__init__.py", line 6, in <module>
    from typing_extensions import Literal
ModuleNotFoundError: No module named 'typing_extensions'

Expected behavior

For an error not to be thrown and Eel import.

System Information

• OS: Windows 10 x64
• Browser: N/A
• Python Distribution: Python 3.9.9

Screenshots

N/A

Additional context

Looking at the diff from the latest release, I can see typing-extensions was added to requirements.txt but it was not added to install_requires in setup.py.

This means when installing modules using requirements.txt, Eel will work, however when installing using pip, install_requires will never get installed as it's not in setup.py.