Python按字母顺序排列3个单词

Question

So I'm writing a code that alphabetizes three words, but I'm trying to be cool, and actually alphabetize it (if both words start with h, it will go to the second letter). I'm basically a beginner, so nothing advanced I'm just using while loops. I got the code to work once, but then it stopped working. Out teacher in the direction said the function we write can't have a return, so here is my code.

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.