Non-sequential substitution in SymPy

Question

I\'m trying to use [SymPy][1] to substitute multiple terms in an expression at the same time. I tried the [subs function][2] with a dictionary as parameter, but found out that i

Answer 1

The current version of sympy provides the keyword simultaneous. The complicated operations in the previous answers are no more necessary:

In [1]: (x*sin(y)).subs([(x,y),(y,x)],simultaneous=True)
Out[1]: y⋅sin(x)