JetBrains offers a fully functional 30-day trial. Students/teachers can get extended trials via GitHub Student Developer Pack.
Even if you find old 2021 activation codes on GitHub:
Students and teachers can get free all-products pack (including PyCharm Professional) for one year, renewable.
👉 Requires a valid school email or documentation.
While not the Professional Edition, the PyCharm Community Edition is free and offers a wide range of functionalities for Python development, including code completion, debugging, and project exploration.