ModelParam.py

class ModelParam:
    """
    parameter object.
    param_fixed: 
        parameters with fixed known value
    names_free: 
        name list of free parameters
    param_list_to_dict(param_list): 
        transfer a list of free params to dict of all params

    usage:
    p0 = ModelParam({'a': 1, 'b':2, 'c':3})
    p1 = p0.fix(c=2).free('a', 'b')
    p1.names_free
    # ['a', 'b']
    p1.param_list_to_dict([3, 4])
    # {'a': 3, 'b':4, 'c':2}
    """

    def __init__(self, param_fixed, names_free=[]):
        """
        param_fixed: dict
        names_free: list of strings
        names_free will overwrite param_fixed.
        """
        self.param_fixed = {**param_fixed}
        for name in names_free:
            self.param_fixed.pop(name, None)
        self.names_free = [*names_free]

    def fix(self, **param_fixed):
        "update fixed params"
        names_free = [name for name in self.names_free if name not in param_fixed]
        return ModelParam({**self.param_fixed, **param_fixed}, names_free)

    def free(self, *names_free):
        "make params free, do not free a parameter multiple times!"
        if [name for name in names_free if name in self.names_free]:
            raise ValueError('duplicated params in names_free')
        return ModelParam(self.param_fixed, [*self.names_free, *names_free])

    def param_list_to_dict(self, param_list):
        """
        param_list: list of values
        """
        param_free = dict(zip(self.names_free, param_list))
        return {**self.param_fixed, **param_free}