There was previous discussion about this in the PR gh-23181 (CC @eagleoflqj). I also have a related PR gh-27353. The symbols function is impossible to use for downstream code that wants to use static ...

x,y,z = symbols('x y z') This way, you define the variables that define the three space dimensions in Cartesian coordinates. If you want to have all four space-time coordinates defined in spherical ...