Question

所以我正在编写一个按字母顺序排列三个单词的代码，但我试图变得很酷，并且实际上按字母顺序排列（如果两个单词都以h开头，它将转到第二个字母）。我基本上是一个初学者，所以没有什么先进的我只是使用while循环。我让代码工作一次，但后来它停止了工作。老师在方向上说我们写的函数不能有回报，所以这是我的代码。

def printInOrder(str1, str2, str3):
    i = 0
    i = int(i)
    list_1 = [str1, str2, str3]
    while i < len(str1) < len(str2) < len(str3):
        if list_1[0][i] = list_1[1][i] = list_1[2][i]:
            i += 1 
        elif list_1[0][i] < list_1[1][i] < list_1[2][i]:
            first = list_1[0]
            second = list_1[1]
            third = list_1[2]
        elif list_1[0][i] < list_1[2][i] < list_1[1][i]:
            first = list_1[0]
            second = list_1[2]
            third = list_1[1]
        elif list_1[1][i] < list_1[0][i] < list_1[2][i]:
            first = list_1[1]
            second = list_1[0]
            third = list_1[2]
        elif list_1[1][i] < list_1[2][i] < list_1[0][i]:
            first = list_1[1]
            second = list_1[2]
            third = list_1[0]
        elif list_1[2][i] < list_1[0][i] < list_1[1][i]:
            first = list_1[2]
            second = list_1[0]
            third = list_1[1]
        else:
            first = list_1[2]
            second = list_1[1]
            third = list_1[0]


    first = str(first)
    second = str(second)
    third = str(third)
    print(first,second,third)

Answer 1

You need to make:

if list_1[0][i] == list_1[1][i] == list_1[2][i]

as == is for comparison and = is for assignment in python. Also

i=int(i)

is not needed as python can recognize 0 as an integer. We need not specify types for variables. Another major error is that you have to increment i at the end of the loop,i=i+1. The condition:

i < len(str1) < len(str2)< len(str3)

is also wrong as this condition is true only if i< len(str1) and len(str1)< len(str2) and len(str2)< len(str3) which need not be the case everytime!Change your logic accordingly.. Using Python's easy built-in functions here is the code:

def printInOrder(str1, str2, str3):
    list_1 = [str1, str2, str3]
    list_1.sort()
    first = list_1[0]
    second = list_1[1]
    third = list_1[2]
    print first,second,third
printInOrder('hat','harry','ham')

Answer 2

In my opinion you are contradicting your teachers intentions with your proposed solution. I strongly assume (s)he would like you to learn about sorting trees or decision trees - so you will only neede if-clauses. See sorting int array with only 3 elements for some solutions and further reading.

Python按字母顺序排列3个单词

2 个答案: