test_lambdarepr.py 文件源码

def test_sum():
    # 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)))"

    assert (lambdify((x, a, b), s)(2, 3, 8) ==
            s.subs([(x, 2), (a, 3), (b, 8)]).doit())

    s = Sum(i * x, (i, a, b))

    l = lambdarepr(s)
    assert l == "(builtins.sum(i*x for i in range(a, b+1)))"

    assert (lambdify((x, a, b), s)(2, 3, 8) ==
            s.subs([(x, 2), (a, 3), (b, 8)]).doit())