def test_sum__2():
s = Sum(i * x, (i, a, b))
l = lambdarepr(s)
assert l == "(builtins.sum(i*x for i in range(a, b+1)))"
args = x, a, b
f = lambdify(args, s)
v = 2, 3, 8
assert f(*v) == s.subs(zip(args, v)).doit()
def test_sum__1():
# In each case, test eval() the lambdarepr() to make sure that
# it evaluates to the same results as the symbolic expression
s = Sum(x**i, (i, a, b))
l = lambdarepr(s)
assert l == "(builtins.sum(x**i for i in range(a, b+1)))"
args = x, a, b
f = lambdify(args, s)
v = 2, 3, 8
assert f(*v) == s.subs(zip(args, v)).doit()
def test_multiple_sums():
s = Sum(i * x + j, (i, a, b), (j, c, d))
l = lambdarepr(s)
assert l == "(builtins.sum(i*x + j for i in range(a, b+1) for j in range(c, d+1)))"
args = x, a, b, c, d
f = lambdify(args, s)
vals = 2, 3, 4, 5, 6
f_ref = s.subs(zip(args, vals)).doit()
f_res = f(*vals)
assert f_res == f_ref
