Python’s Windows installer is very good nowadays, but there are a couple of tweaks you can apply to make it easier for Python to use less of your C Drive, which is especially useful if you have a small SSD.
What I end up doing is:
Step 1. Install Python to D Drive. For instance, a folder like D:\ProgramsDir\Python\Python38. I typically don’t add Python to the PATH because I have a doskey alias that adds the required directories to my PATH inside of a Command Prompt, but people who use a lot of Python may find it useful to let the installer add Python (and Scripts, etc) to the PATH.
Step 2. Store per-user site-packages on D. Set the user environment
variable PYTHONUSERBASE to point the per-user site-packages directory to, for
instance, D:\Data\PyData. See PEP
370 for more details.
Step 3. Virtual Environments. The other thing that chews up space on C: is
virtual environments. To get virtual environments on Windows, I install
virtualenvwrapper-win (using pip). I then set the user environment variable
WORKON_HOME to D:\Data\PyEnvs. Virtualenvs are now created under this
directory.