March 2022
Intermediate to advanced
522 pages
13h 52m
Chinese
Content preview from Python语言及其应用（第2版）
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字符串
｜
63
5.15
对齐
现在来看几个与排版布局相关的函数。假定字符串要在特定空间范围内（这里是
30
个空
格的长度）对齐。
在
30
个空格长度内将字符串居中：
>>> setup.center(30)
' a duck goes into a bar... '
左对齐：
>>> setup.ljust(30)
'a duck goes into a bar... '
右对齐：
>>> setup.rjust(30)
' a duck goes into a bar...'
接下来还有更多的对齐方式。
5.16
格式化
你已经看到可以使用
+
拼接
字符串。下面看一下如何使用各种格式在字符串中进行插值。
可以以此来生成报告、表单以及其他需要有适合外观的输出。
除了上一节介绍的函数，
Python
还有
3
种字符串格式化方法。
•
旧式样（
Python 2
和
Python 3
均支持）
•
新式样（
Python 2.6
及以上版本支持）
• f
字符串（
Python 3.6
及以上版本支持）
5.16.1
旧式样
：
%
旧式字符串格式化采用的形式为
format_string
%
data
。格式化字符串内是插值序列。表
5-1
说明了最简单的序列就是
%
后面跟上一个字母，指明要被格式化的数据类型。
表5-1：转换类型
%s
字符串
%d
十进制整数
%x
十六进制整数
%o
八进制整数
%f
十进制浮点数
%e
指数型浮点数
%g
十进制浮点数或指数浮点数
%%
字面
%
64
｜
第
5
章
%s
可用于任何数据类型，
Python
会将其格式化为没有多余空格的字符串。
下面是一些简单的示例。首先是整数： ...
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.