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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236
｜
第
14
章
斜线技巧利用了
Python
的“魔术方法”（参见
10.8
节 ）。
Path
对象可以告诉你一些自身的
信息：
>>> file_path.name
'snort.txt'
>>> file_path.suffix
'.txt'
>>> file_path.stem
'snort'
可以像文件名或路径名字符串那样将
file_path
传给
open()
。
来看看如果在其他系统中运行该程序，或是需要生成其他系统的路径名时会发生什么：
>>> from pathlib import PureWindowsPath
>>> PureWindowsPath(file_path)
PureWindowsPath('eek/urk/snort.txt')
>>> print(PureWindowsPath(file_path))
eek\urk\snort.txt
具体细节参见相关文档。
14.6
BytesIO
和
StringIO
你已经看到了如何修改内存中的数据以及如何读取
/
写入文件。如果要处理的是内存中的
数据，但调用的函数只接受文件（或者是相反的情况），那么该怎么办呢？你希望在无须
读写临时文件的情况下，修改和传递这些字节或字符。
可以使用
io.BytesIO
和
io.StringIO
，前者用于二进制数据（
bytes
），后者用于文本数据
（
str
）。二者将数据包装成
类文件对象
（
file-like object
），适用于本章介绍的所有文件函数。
用例之一是数据格式转换。接下来，我们将其应用于读写图像数据的 ...
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