I am new to sympy, and I am following a guide to using it for physics.

There's a line which says: smp.symbols(r'\theta_1 \theta_2', cls=smp.Function)

What does the r before the '\theta_1 \theta_2' means? I have not been able to find anything...

So far, I have noticed that removing it

Screenshot without the r, using jupyter

kind of messes with the variable name, given that it has a \ for "LaTeX".

Thanks for any insights you may provide!!

CodePudding user response：

r"xxx" indicates a "raw string", in which backslash escapes are not processed. The string "\theta" by itself contains 5 characters: a tab, and the letters "heta". But the string r"\theta" contains 6 characters: a backslash, a 't', and then 'heta'.

You can also write "\\theta_1 \\theta_2", but raw strings save you from having to double the backslashes.