Turing automata in Python

Question

class Tape(object):

    blank_symbol = " "

    def __init__(self,
                 tape_string = ""):
        self.__tape = dict((enumerate(tape_string)))
        # last line is equivalent to the following three lines:
        #self.__tape = {}
        #for i in range(len(tape_string)):
        #    self.__tape[i] = input[i]

    def __str__(self):
        s = ""
        min_used_index = min(self.__tape.keys()) 
        max_used_index = max(self.__tape.keys())
        for i in range(min_used_index, max_used_index):
            s += self.__tape[i]
        return s    

    def __getitem__(self,index):
        if index in self.__tape:
            return self.__tape[index]
        else:
            return Tape.blank_symbol

    def __setitem__(self, pos, char):
        self.__tape[pos] = char 


class TuringMachine(object):

    def __init__(self, 
                 tape = "", 
                 blank_symbol = " ",
                 initial_state = "",
                 final_states = None,
                 transition_function = None):
        self.__tape = Tape(tape)
        self.__head_position = 0
        self.__blank_symbol = blank_symbol
        self.__current_state = initial_state
        if transition_function == None:
            self.__transition_function = {}
        else:
            self.__transition_function = transition_function
        if final_states == None:
            self.__final_states = set()
        else:
            self.__final_states = set(final_states)

    def get_tape(self): 
        return str(self.__tape)

    def step(self):
        char_under_head = self.__tape[self.__head_position]
        x = (self.__current_state, char_under_head)
        if x in self.__transition_function:
            y = self.__transition_function[x]
            self.__tape[self.__head_position] = y[1]
            if y[2] == "R":
                self.__head_position += 1
            elif y[2] == "L":
                self.__head_position -= 1
            self.__current_state = y[0]

    def final(self):
        if self.__current_state in self.__final_states:
            return True
        else:
            return False

I am trying to implement Turing automata in Python. Can you tell me why this code doesn't work? e machine operates on an infinite[4] memory tape divided into discrete cells.[5] The machine positions its head over a cell and "reads" (scans)[6] the symbol there. Then, as per the symbol and its present place in a finite table[7] of user-specified instructions, the machine (i) writes a symbol (e.g., a digit or a letter from a finite alphabet) in the cell (some models allowing symbol erasure or no writing) then (ii) either moves the tape one cell left or right (some models allow no motion, some models move the head),[9] then (iii) (as determined by the observed symbol and the machine's place in the table) either proceeds to a subsequent instruction or halts the computation.

Answer 1

Before adding i to list, convert it to float by float(i).

for i in lines:
    print(i)
    if(i != " "):
        if(a % 4 == 0 and a != 1):
            second.append(float(i))
            tuple(tmp)
            first.append(tmp)
            tmp = []
        else:
            tmp.append(float(i))
        a+=1