使用数组时无法解决“列表索引超出范围”错误

我正在尝试编写一个“现金箱”式密码破解程序,它可以旋转拨号盘,每个拨号盘上都有每个字符,直到找到答案。我对Python(以及一般的编码)相当陌生,但在很多帮助下,我能够用数字和字母(大写和无头)完成这项工作

现在我正在尝试构建它,以便只检查数字和无头字母,而不是大写字母。以下是我得到的:

def method_2(num_pass_wheels):
    result = False
    still_searching = True
    print()
    print("Using method 2 and searching with " + str(num_pass_wheels) + " characters.")
    wheel = " abcdefghijklmnopqrstuvwxyz0123456789"
# set all of the wheels to the first position
    pass_wheel_array = array('i', [1, 0, 0, 0, 0, 0, 0, 0, 0])

    while still_searching:
        ourguess_pass = ""
        for i in range(0, num_pass_wheels):  # once for each wheel
            if pass_wheel_array[i] > 0:
                ourguess_pass = wheel[pass_wheel_array[i]] + 
    ourguess_pass
        print ("trying [" + ourguess_pass + "]")
        if (check_pass(which_password, ourguess_pass)):
            print ("Success! Password  " + str(which_password) + " is " + ourguess_pass)
            still_searching = False   # we can stop now - we found it!
            result = True

 # spin the rightmost wheel and if it changes, spin the next one over and so on
        carry = 1
        for i in range(0, num_pass_wheels):  # once for each wheel
            pass_wheel_array[i] = pass_wheel_array[i] + carry
            carry = 0
            if pass_wheel_array[i] > 62:
                pass_wheel_array[i] = 1
                carry = 1
                if i == (num_pass_wheels - 1):
                    still_searching = False

    return result

错误消息指向:

line 341, in <module>
    foundit = method_2(8)

line 188, in method_2
    ourguess_pass = wheel[pass_wheel_array[i]] + ourguess_pass

并抛出错误:

IndexError: string index out of range

我知道这跟我把“轮子”上的大写字母去掉有关,但我不知道如何去修复它。有什么帮助吗?