A frequent newbie mistake is to call shell commands from inside the interactive interpreter. Most common is to call Python itself.

Here is an example where a Python instructor was allegedly unable to diagnose the issue for their students:

https://windowsquestions.com/2021/10/09/syntaxerror-invalid-syntax-perhaps-you-forgot-a-comma/


I think it would be a nice feature if the compiler recognised obvious cases of "user tried to call Python from the Python prompt", and suggested a fix. If the statement matches the regex r"python\s+" the error message might say "it looks like you are trying to run a shell command at the Python prompt" rather than suggest a missing comma.

I think that "trying to run a shell command" might not be easy to understand by a beginner.

If the special case of r"python\s+" is added, perhaps r"pip\s+" should be considered as well since many sites on the Internet suggest to install packages using "pip install ..." instead of "python -m pip install ..."

+1 for adding r"pip\s" as a special case as well. A few months ago, I was trying to (remotely) help a beginner friend debug why his attempt to install a library wasn't working. It took me ages before I realised he was entering it into the interactive REPL rather than a terminal window.

Agreed. 'pip ...' not working is a recurring question on stackoverflow, usually from an IDLE user.  'python' is much rarer.  Note that IDLE's shell may be a beginner's only exposure to the word 'shell'.  The standard Windows shell is the Command Prompt console, so one has to say 'Command Prompt command'.  Would 'bash command' work elsewhere?