Python, не работают циклы в самописном компиляторе BrainFuck

 def BrainFuck(code): 
    memory = [0] * 100 
    location = 0 
    for i in range(len(code)): 
        command = code[i] 
        if command == ">": 
             location += 1 
        elif command == "<": 
            location -= 1 
        elif command == "+": 
            memory[location] += 1 
        elif command == "-": 
            memory[location] -= 1 
        elif command == ".": 
            print(chr(memory[location]), end="") 
        elif command == ",": 
            memory[i] = int(input()) 
        elif command == "[": 
            if memory[location] == 0: 
                cycle = 1 
                while cycle > 0: 
                    i += 1 
                    if code[i] == "[": 
                        cycle += 1 
                    elif code[i] == "]": 
                        cycle -= 1 
        elif command == "]": 
            if memory[location] != 0: 
                cycle = 1 
                while cycle > 0: 
                    i -= 1 
                    if code[i] == "]": 
                        cycle += 1 
                    elif code[i] == "[": 
                        cycle -= 1 

 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.>++++++++++++++++++++++++++++++++.>+++[<<.>.>-]