2.16 以指定列宽格式化字符串

## 问题 你有一些长字符串，想以指定的列宽将它们重新格式化。 ## 解决方案 使用 `textwrap` 模块来格式化字符串的输出。比如，假如你有下列的长字符串： s = "Look into my eyes, look into my eyes, the eyes, the eyes, \ the eyes, not around the eyes, don't look around the eyes, \ look into my eyes, you're under." 下面演示使用 `textwrap` 格式化字符串的多种方式： >>> import textwrap >>> print(textwrap.fill(s, 70)) Look into my eyes, look into my eyes, the eyes, the eyes, the eyes, not around the eyes, don't look around the eyes, look into my eyes, you're under. >>> print(textwrap.fill(s, 40)) Look into my eyes, look into my eyes, the eyes, the eyes, the eyes, not around the eyes, don't look around the eyes, look into my eyes, you're under. >>> print(textwrap.fill(s, 40, initial_indent=' ')) Look into my eyes, look into my eyes, the eyes, the eyes, the eyes, not around the eyes, don't look around the eyes, look into my eyes, you're under. >>> print(textwrap.fill(s, 40, subsequent_indent=' ')) Look into my eyes, look into my eyes, the eyes, the eyes, the eyes, not around the eyes, don't look around the eyes, look into my eyes, you're under. ## 讨论 `textwrap` 模块对于字符串打印是非常有用的，特别是当你希望输出自动匹配终端大小的时候。你可以使用 `os.get_terminal_size()` 方法来获取终端的大小尺寸。比如： >>> import os >>> os.get_terminal_size().columns 80 >>> `fill()` 方法接受一些其他可选参数来控制tab，语句结尾等。参阅 [textwrap.TextWrapper文档](https://docs.python.org/3.3/library/textwrap.html#textwrap.TextWrapper) 获取更多内容。