在设定的行范围内读取文本文件 [英] Reading in a text file in a set line range

问题描述

是否可以从文本文件中读取设置的行范围，例如从第20行到第52行?

Is it possible to read in from a text file a set line range for example from line 20 to 52?

我正在打开文件并像这样读取文件:

I am opening the file and reading the file like this:

text_file = open(file_to_save, "r")
line = text_file.readline()

但只想将数据保存在设定的范围内，或者如果可能的话，可以从包含---数据---的一行后到包含-数据结尾-的另一行中读入

but only want to save the data in a set range or if it possible to read in from a after a line containing --- data --- to another line containing -- end of data --

我已经浏览了文档和在线示例，只能找到指定换行符或其他内容的示例

I have looked through the documentation and online examples and can only find examples that specify a new line or something

推荐答案

您可以使用

You can use itertools.islice() on the file object and use iteration to read only specific lines:

import itertools

with open(file_to_save, "r") as text_file:
    for line in itertools.islice(text_file, 19, 52):
         # do something with line

将读取第20行到第52行； Python使用基于0的索引，因此第1行的编号为0.

would read lines 20 through to 52; Python uses 0-based indexing, so line 1 is numbered 0.

使用文件对象作为迭代器可以为您带来很大的灵活性；您可以通过在文件对象上调用next() 来阅读更多行，例如，在执行此操作时将指针"行推进.

Using the file object as an iterator gives you a lot of flexibility; you can read extra lines by calling next() on the file object, for example, advancing the line 'pointer' as you do so.

以可迭代方式使用文件时， 不要使用readline() ；这两种技术不容易混用.

When using the file as an iterable, don't use readline(); the two techniques are not easily mixed.

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