Python:在文本文件中搜索字符串后查找值 [英] Python: Finding values after searching for a string in a text files

问题描述

我是 Python 世界的新手，我正在尝试从多个文本文件中提取值.我可以用循环打开文件，但我正在寻找一种直接的方法来搜索字符串，然后在它之后返回值.

I'm new to the world of python and I'm trying to extract values from multiple text files. I can open up the files fine with a loop, but I'm looking for a straight forward way to search for a string and then return the value after it.

我的结果文本文件看起来像这样

My results text files look like this

SUMMARY OF RESULTS
Max tip rotation =,-18.1921,degrees
Min tip rotation =,-0.3258,degrees
Mean tip rotation =,-7.4164,degrees
Max tip displacement =,6.9956,mm
Min tip displacement =,0.7467,mm
Mean tip displacement = ,2.4321,mm
Max Tsai-Wu FC =,0.6850
Max Tsai-Hill FC =,0.6877

所以我希望能够搜索说Max Tsai-Wu ="，它返回 0.6850我希望能够搜索字符串，因为每个变量的位置在以后可能会发生变化.

So I want to be able to search for say 'Max Tsai-Wu =,' and it return 0.6850 I want to be able to search for the string as the position of each variable might change at a later date.

很抱歉发布这么简单的问题，只是似乎无法找到一种直接可靠的方法来找到它.

Sorry for posting such an easy question, just can't seem to find a straight forward robust way of finding it.

任何帮助将不胜感激！马特

Any help would be greatly appreciated! Matt

推荐答案

你可以使用正则表达式:

You can make use of regex:

import re


regexp = re.compile(r'Max Tsai-Wu.*?([0-9.-]+)')
with open('input.txt') as f:
    for line in f:
        match = regexp.match(line)
        if match:
            print match.group(1)

印刷品:

0.6850

UPD:将结果放入列表

UPD: getting results into the list

import re


regexp = re.compile(r'Max Tsai-Wu.*?([0-9.-]+)') 
result = []
with open('input.txt') as f:
    for line in f:
        match = regexp.match(line)
        if match:
            result.append(match.group(1))

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