test_unit_conversion.py 文件源码

def test_simple_scaling():
    Quantity.set_prefs(spacer=None, show_label=None, label_fmt=None, label_fmt_full=None)
    q=Quantity('1kg')
    assert q.render() == '1 kg'
    assert q.render(scale=0.001, show_units=False) == '1'
    with pytest.raises(KeyError, message="Unable to convert between 'fuzz' and 'g'."):
        q.render(scale='fuzz')

    q=Quantity('1', units='g', scale=1000)
    assert q.render() == '1 kg'
    assert q.render(scale=(0.0022046, 'lbs')) == '2.2046 lbs'

    q=Quantity('1', scale=(1000, 'g'))
    assert q.render() == '1 kg'
    assert q.render(scale=lambda v, u: (0.0022046*v, 'lbs')) == '2.2046 lbs'

    def dB(v, u):
        return 20*math.log(v, 10), 'dB'+u

    def adB(v, u):
        return pow(10, v/20), u[2:] if u.startswith('dB') else u

    q=Quantity('-40 dBV', scale=adB)
    assert q.render() == '10 mV'
    assert q.render(scale=dB) == '-40 dBV'