将长字符串换成换行符的好方法吗？

Question

在我的项目中，我有一堆从文件中读取的字符串。当在命令控制台中打印时，其中大多数字符的长度超过80个字符并环绕，看起来很丑。

我希望能够让Python读取该字符串，然后测试其长度是否超过75个字符。如果是这样，则将字符串分成多个字符串，然后在新行上一个接一个地打印。我也希望它很聪明，而不是断断续续。即"The quick brown <newline> fox..."代替"the quick bro<newline>wn fox..."。

我试过修改类似的代码，该代码会在设置长度后将字符串截断，但只是将字符串丢弃而不是将其放在新行中。

我可以使用哪些方法来完成此任务？

Answer 1

您可以使用textwrap模块：

>>> import textwrap
>>> strs = "In my project, I have a bunch of strings that are read in from a file. Most of them, when printed in the command console, exceed 80 characters in length and wrap around, looking ugly."
>>> print(textwrap.fill(strs, 20))
In my project, I
have a bunch of
strings that are
read in from a file.
Most of them, when
printed in the
command console,
exceed 80 characters
in length and wrap
around, looking
ugly.

帮助
上textwrap.fill：

>>> textwrap.fill?

Definition: textwrap.fill(text, width=70, **kwargs)
Docstring:
Fill a single paragraph of text, returning a new string.

Reformat the single paragraph in 'text' to fit in lines of no more
than 'width' columns, and return a new string containing the entire
wrapped paragraph.  As with wrap(), tabs are expanded and other
whitespace characters converted to space.  See TextWrapper class for
available keyword args to customize wrapping behaviour.

使用regex，如果你不想合并一行到另一行：

import re


strs = """In my project, I have a bunch of strings that are.
Read in from a file.
Most of them, when printed in the command console, exceed 80.
Characters in length and wrap around, looking ugly."""

print('\n'.join(line.strip() for line in re.findall(r'.{1,40}(?:\s+|$)', strs)))

# Reading a single line at once:
for x in strs.splitlines():
    print '\n'.join(line.strip() for line in re.findall(r'.{1,40}(?:\s+|$)', x))

输出：

In my project, I have a bunch of strings
that are.
Read in from a file.
Most of them, when printed in the
command console, exceed 80.
Characters in length and wrap around,
looking ugly.