@check of _init__ fails

[martinwk]

Say I have this class:

class SomeClass
    @ureg.check(None, None,
                '[length] ** 2 / [time]',
                )
    def __init__(self, name='test',
                 D_s=2.4e-15 * ureg('m ** 2 / s'),
                       ):

        print D_s
        self.name  = name

    @ureg.check(None, None, None, '=A/A')  # this is a hack for dimensionless
    def testFunc(self, name='aaa',
                 Kf=300. * ureg('(g/g_substrate)*(L/g) ** 0.3'),
                 n_inv=0.3 * ureg.dimensionless):
         print self
         print name
         print Kf
         print n_inv

when I create some instance of the class,

some_instance = SomeClass()

it fails with the error:

  File "C:\Users\korevma\AppData\Local\Continuum\Anaconda2\lib\site-packages\pint\registry_helpers.py", line 210, in wrapper
  
if dim and value.dimensionality != dim:
AttributeError: 'NoneType' object has no attribute 'dimensionality'

When I remove the check for the init() and then run the testFunc()

some_instance.testFunc()

no errors are returned. What am I doing wrong

[hgrecco]

This works for me with master.

import pint
ureg = pint.UnitRegistry()

class SomeClass:
    @ureg.check(None, None, '[length] ** 2 / [time]')
    def __init__(self, name, D_s):
        print(name, D_s)

    @ureg.check(None, None, '[length] ** 2 / [time]')
    def test(self, name, D_s):
        print(name, D_s)

x = SomeClass('Help!', 3 * ureg.m * ureg.m / ureg.s)
x.test('Please!', 1 * ureg.m * ureg.m / ureg.s)

It might be a problem with the default values. We should fixed together with #439

[martinwk]

Yes, removing default values makes it work for me too. Which solves this issue to some extent.

I would like to have the default values though. I am looking forward to your fix :)

[hgrecco]

Closing. Feel free to reopen if you keep encountering this problem.