def empty(self):
        for k in list(self.children.keys()):
            self.remove_child(self.children[k])
Efficiently extract the coefficient of a summation.
dataset/ETHPy150Open dddomodossola/remi/remi/gui.py/Tag.empty--crossover with--dataset/ETHPy150Open sympy/sympy/sympy/vector/basisdependent.py/BasisDependent.as_coeff_add