test_lambdify.py 文件源码

def test_dummification():
    t = symbols('t')
    F = Function('F')
    G = Function('G')
    #"\alpha" is not a valid python variable name
    #lambdify should sub in a dummy for it, and return
    #without a syntax error
    alpha = symbols(r'\alpha')
    some_expr = 2 * F(t)**2 / G(t)
    lam = lambdify((F(t), G(t)), some_expr)
    assert lam(3, 9) == 2
    lam = lambdify(sin(t), 2 * sin(t)**2)
    assert lam(F(t)) == 2 * F(t)**2
    #Test that \alpha was properly dummified
    lam = lambdify((alpha, t), 2*alpha + t)
    assert lam(2, 1) == 5
    raises(SyntaxError, lambda: lambdify(F(t) * G(t), F(t) * G(t) + 5))
    raises(SyntaxError, lambda: lambdify(2 * F(t), 2 * F(t) + 5))
    raises(SyntaxError, lambda: lambdify(2 * F(t), 4 * F(t) + 5))