How can I get a list of the symbols in a sympy expression?

Question

For example, if I run

import sympy
x, y, z = sympy.symbols(\'x:z\')
f = sympy.exp(x + y) - sympy.sqrt(z)

is there any method of f

Answer 1

A very useful attribute is atoms

x, y, z = sympy.symbols('x:z')
expr1 = sympy.exp(x + y) - sympy.sqrt(z)
display(expr1.free_symbols)
display(expr1.atoms(sympy.Symbol))

{