描述

读取文件特定行

问题 Problem

读取文件的指定一行

4.5.2 Solution

解决 Solution

The standard linecache module makes this a snap:

使用标准模块linecache处理，手到擒来！

import linecache
theline = linecache.getline(thefilepath, desired_line_number)

讨论 Discussion

The standard linecache module is usually the optimal Python solution for this task, particularly if you have to do this repeatedly for several of a file's lines, as it caches the information it needs to avoid uselessly repeating work. Just remember to use the module's clearcache function to free up the memory used for the cache, if you won't be getting any more lines from the cache for a while but your program keeps running. You can also use checkcache if the file may have changed on disk and you require the updated version.

使用标准模块linecache处理这个任务，一般来说是最佳方法。由于lincecache缓存了文件(行?)的信息，当需要多次提取文件的某些特定行时，可以避免无用的重复操作。

如果不再需要读取文件特定行而且脚本需要继续运行，应该使用linecache的clearcache方法释放缓存占用的内存。

如果硬盘上文件有了变化，可以使

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PyCkBk-4-5

描述

问题 Problem

解决 Solution

讨论 Discussion

参考 See Also