python - 自动换行算法未按预期打印

Question

我想开发一种递归自动换行算法，它采用指定的字符串和换行长度(一行中的最大字符数)返回输入长度的换行输出。我不希望它分解单词。例如，This is the first paragraph that you need to input with length 20 returns as:

This is the first
paragraph that you
need to input

但是，我的函数当前打印:

This is the first paragraph
that you need to input

我的代码:

def wrap(text, lineLength):

    temp=text.find(" ",lineLength-1)
    if temp == -1:
        return text
    else:
        return text[:temp+1]+'\n'+wrap(text[temp+1:], lineLength)

print wrap("This is the first paragraph that you need to input", 20);

为什么这没有按照我的预期进行，我该如何解决？

Answer 1

通过一些更改您的代码可以工作:

def wrap(text, lineLength):
    if len(text) <= lineLength: return text
    temp = text.rfind(" ", 0, lineLength - 1)
    if temp == -1: 
        return text
    else:
        return text[:temp+1]+'\n'+wrap(text[temp+1:], lineLength)

有了这个输出:

This is the first 
paragraph that you 
need to input

但您可能还想在没有空格可分隔时强制使用连字符:

def wrap(text, lineLength):
    if len(text) <= lineLength: return text
    temp = text.rfind(" ", 0, lineLength - 1)
    if temp == -1: 
        return text[:lineLength - 1] + '-\n' + wrap(
            text[lineLength - 1:], lineLength)
    else:
        return text[:temp+1] + '\n' + wrap(text[temp+1:], lineLength)

print wrap("Thisisthefirstparagraphthatyouneed to input", 20)

这导致:

Thisisthefirstparag-
raphthatyouneed to 
input