Question

我不知道为什么会这样。也不要告诉我使用python的内置函数，因为这是为某些实际设计而不是实际使用的。它是二进制到十进制的。它与变量'index'

有一个索引错误

    print('Please choose from the list below:')
    print('')
    print('1) Convert from decimal/denary to binary; ')
    print('2) Covert from binary to denary/decimal; ') #Main Menu
    print('3) Infomation and settings (coming soon);')
    print('4) Exit. ')
    print('')
    menu_choice = str(input('Enter your choice here: ')) #User inputs choice here

    if menu_choice == '1':
        dec_binary()
    elif menu_choice == '2':
        binary_dec()
    elif menu_choice == '3':
        print('By Callum Suttle')
    else:
        return 'Thank You'

def dec_binary():                                                          #Module 1: decimal to binary
    dec = int(input('Enter a number in decimal up to 255: '))              #Checks The number is an ok size, could be made bigger         
    while dec > 255:
        dec = int(input('Enter a number up to 255, no more: '))

    power = int(7)     #change 7 to make bigger by 1 digit                                                     
    convert = []

    while power > -1:      #until power goes below zero
        if dec - pow(2, power) >= 0:  #if entered number subtract 2 to the power of var-pow returns posotive number
            convert.append(1)
            power -=1                 # add a 1
            dec = dec - pow(2, power) >= 0
        else:
            convert.append(0)#if not add a zero
            power -=1
    print('')
    print(convert) # print completed number
    print('')
    binary_decimal_converter() #back to main menu

def binary_dec():
    anwser = 0
    l_bi = str(input('Enter a number in binary up to 7 digits: '))
    while len(l_bi) != 7:    #checks for correct length
        l_bi = str(input('Enter a number in binary up to 7 digits, you may add zeros before: '))
    power = 7       #size can be increased by using this
    index = 0
    while index > 6:  #until every power has been checked (in reverse order)
        if l_bi[index] == '1':  #if the digit is equal to 1 
            anwser += pow(2, power)  #add that amount
            power -= 1 #take the power to check next                                          #why is this broken
            index += 1 # add another index to check previous 
        else:
            power -= 1 #as above
            index += 1   #/\
    print('')
    print(anwser) #prints result
    print('')
    binary_decimal_converter() #main menu

Answer 1

这似乎不对

index = 0
while index > 6:  #until every power has been checked (in reverse order)
    ...

你永远不会进入这个循环，是吗？

更好的循环就像是

for i, bit in enumerate(l_bi):
   answer += int(bit) * pow(2, 7-i)

另外，既然你刚刚练习，你应该找到一种更好的方法从菜单跳转到功能并返回。你正在进行递归调用，这是浪费堆栈，即你的函数实际上永远不会完成，只是调用越来越多的函数。

Answer 2

一些修正：

def binary_dec():
    anwser = 0 
    l_bi = str(input('Enter a number in binary up to 7 digits: '))
    while len(l_bi) > 7:   # LOOP UNTIL LENGTH IS LESS THAN 7 
        l_bi = str(input('Enter... : '))
    power = len(l_bi) - 1  # directly set the power based on length
    index = 0 
    while index < len(l_bi): # CORRECT LOOP CONDITION

打破二进制转换器索引错误

2 个答案: