Question

这是我到目前为止所做的：

while len(words) != 5:
        words = raw_input("Enter a 5 worded sentence: ").split()
        print "Try again. The word count is:", wordCount
if len(words) == 5:
        print "Good! The word count is 5!"

问题是我得到了这个：

Enter a 5 worded sentence: d d d d
Try again. The word count is: 4
Enter a 5 worded sentence: d d d d d d 
Try again. The word count is: 4
Enter a 5 worded sentence: d d d d d 
Try again. The word count is: 4
Good! The word count is 5!

当我输入多于或少于5个单词时，它会保持该单词的数量并且不会改变。

Answer 1

由于Python没有像其他语言那样的do-while循环，这个习惯用法可以防止raw_input函数的重复，并确保循环运行至少一次。确保在获得新输入后更新word_count。

while 1:
    words = raw_input("Enter a 5 worded sentence: ").split()
    word_count = len(words)
    if word_count == 5: break
    print "Try again. The word count is:", word_count
print "Good! The word count is 5!"

Answer 2

您只需重新订购一些逻辑：

# prompt before entering loop
words = raw_input("Enter a 5 worded sentence: ").split()
while len(words) != 5:
        print "Try again. The word count is:", len(words)
        words = raw_input("Enter a 5 worded sentence: ").split()

# no need to test len again
print "Good! The word count is 5!"

Answer 3

接受输入后，应在循环内更新变量wordCount。只有这样它才会反映出新的价值。这样的事情： -

while len(words) != 5:
    words = raw_input("Enter a 5 worded sentence: ").split()
    wordCount = len(words)
    print "Try again. The word count is:", wordCount
if len(words) == 5:
    print "Good! The word count is 5!"

Answer 4

我认为您的代码段缺少部分。无论如何，您应该在wordCount之后评估raw_input，以便使用新值进行更新。

wordCount = 0
while wordCount != 5:
    words = raw_input("Enter a 5 worded sentence: ").split()
    wordCount = len(words)
    print "Try again. The word count is:", wordCount

print "Good! The word count is 5!"

Answer 5

def xlen(string_data):
    try:
        count = 0
        while 1:
            string_data[count]
            count = count + 1
    except(IndexError):
        print count

xlen('hello')

Python：如何使用while循环并输出正确的字数

5 个答案: