from sympy.strategies.tools import subs, typed from sympy.strategies.rl import rm_id from sympy.core.basic import Basic from sympy.core.singleton import S def test_subs(): from sympy.core.symbol import symbols a, b, c, d, e, f = symbols('a,b,c,d,e,f') mapping = {a: d, d: a, Basic(e): Basic(f)} expr = Basic(a, Basic(b, c), Basic(d, Basic(e))) result = Basic(d, Basic(b, c), Basic(a, Basic(f))) assert subs(mapping)(expr) == result def test_subs_empty(): assert subs({})(Basic(S(1), S(2))) == Basic(S(1), S(2)) def test_typed(): class A(Basic): pass class B(Basic): pass rmzeros = rm_id(lambda x: x == S(0)) rmones = rm_id(lambda x: x == S(1)) remove_something = typed({A: rmzeros, B: rmones}) assert remove_something(A(S(0), S(1))) == A(S(1)) assert remove_something(B(S(0), S(1))) == B(S(0))