PyRoll From Dict Extension

This extension is meant to create PyRolL objects from plain dict structures.

Import PyRolL Objects

For example to create a RollPass instance with the related Roll and Groove objects use the following:

from pyroll.from_dict import from_dict

roll_pass = from_dict({
    '__ctor__': 'RollPass',
    'gap': 0.001,
    'roll': {
        '__ctor__': 'Roll',
        'nominal_radius': 0.1,
        'rotational_frequency': 1,
        'groove': {
            '__ctor__': 'CircularOvalGroove',
            'r1': 0.002,
            'r2': 0.02,
            'depth': 0.002
        }
    }
}, {})

The class resp. factory function can be given with the __ctor__ key. By default, class and object names therein are resolved in the pyroll.core namespace. The key can be changed with the pyroll.from_dict.Config.FACTORY_KEY config parameter. The second argument to from_dict is a dict of namespaces to use additionally for resolving constructor names. The key must be than used as prefix to the object name in dot notation like in the following example (although you may resolve RollPass without prefix, because it is in the pyroll.core namespace).

from pyroll.from_dict import from_dict

roll_pass = from_dict({
    '__ctor__': 'pr.RollPass',
    ...
}, {"pr": "pyroll.core"})

Import Whole Input Sets

The second main function of this package is dict_input. It reads from a larger dict structure containing an incoming profile, a pass sequence and namespace definitions. It returns a tuple of in profile and pass sequence.

from pyroll.from_dict import dict_input

in_profile, sequence = dict_input({
    'namespaces': {'pr': 'pyroll.core', 'np': 'numpy'},
    'in_profile': {
        '__ctor__': 'Profile.round',
        'diameter': 0.01,
        'strain': 0,
        'temperature': 1273.15,
        'density': 'func: 7.85 / (1 + 3 * 3.5e-3 * (self.temperature - 273.15))'
    },
    'unit': [
        {
            '__ctor__': 'RollPass',
            'gap': 0.001,
            'roll': {
                '__ctor__': 'Roll',
                'nominal_radius': 0.1,
                'rotational_frequency': 1,
                'groove': {
                    '__ctor__': 'CircularOvalGroove',
                    'r1': 0.002,
                    'r2': 0.02,
                    'depth': 0.002
                }
            }
        }
    ]
})

The namespaces are used in resolving all specified objects. The keys for namespaces, in profile and unit/sequence can be configured with pyroll.from_dict.Config.NAMESPACES_KEY, pyroll.from_dict.Config.IN_PROFILE_KEY and pyroll.from_dict.Config.UNIT_KEY. The value of the unit can be a single unit definition or a list. The list will be automatically converted into an instance of PassSequence.

As you can see in the density field of the in profile, you may give explicit hook functions by providing a string of the structure "func: <some expression> similar to a lambda function. Whitespace in this string is ignored. The only argument to this function is self, the reference to the respective instance. The function expression will be compiled and executed using eval(). You may use all modules defined in the namespaces from within the function (so for example you may use np for numpy here.