test_quantities.py 文件源码

def test_units():
    assert convert_to((5*m/s * day) / km, 1) == 432
    assert convert_to(foot / meter, meter) == Rational('0.3048')
    # amu is a pure mass so mass/mass gives a number, not an amount (mol)
    # TODO: need better simplification routine:
    assert str(convert_to(grams/amu, grams).n(2)) == '6.0e+23'

    # Light from the sun needs about 8.3 minutes to reach earth
    t = (1*au / speed_of_light) / minute
    # TODO: need a better way to simplify expressions containing units:
    t = convert_to(convert_to(t, meter / minute), meter)
    assert t == 49865956897/5995849160

    # TODO: fix this, it should give `m` without `Abs`
    assert sqrt(m**2) == Abs(m)
    assert (sqrt(m))**2 == m

    t = Symbol('t')
    assert integrate(t*m/s, (t, 1*s, 5*s)) == 12*m*s
    assert (t * m/s).integrate((t, 1*s, 5*s)) == 12*m*s