$ python3
Python 3.8.6 (default, Nov 18 2020, 23:56:33)
[GCC 9.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> quit
Use quit() or Ctrl-D (i.e. EOF) to exit
>>> q = quit
>>> quit = "foo"
>>> quit
'foo'
>>> quit()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: 'str' object is not callable
>>> q()
$