convert

import math

class MyProcessingClass:


    def __init__(self, str_list):

        self._str_list = str_list
        self._float_list = []
        self._strings_to_floats()

    # the function to convert the list
    # of strings into a list of floats
    def _strings_to_floats(self):

        for i in self._str_list:
            try:
                num = int(i)
                if not math.isnan(num):
                    self._float_list.append(num)
            except ValueError:
                pass

    # process the list of floats in some way
    def process_input(self):
        print(self._float_list)


input_1 = list("123abc")
proc_1 = MyProcessingClass(input_1)
proc_1.process_input()

input_2 = ['1.2', '2', 'NaN', 'foo', '0x8', 'bar']
proc_2 = MyProcessingClass(input_2)
proc_2.process_input()