在python中的文本文件中搜索字符串

Question

I'm using Python to search a large text file for a certain string, below the string is the data that I am interested in performing data analysis on.

def my_function(filename, variable2, variable3, variable4):
array1 = []

with open(filename) as a:
    special_string = str('info       %d        info =*' %variable3)
    for line in a:
        if special_string == array1:
            array1 = [next(a) for i in range(9)]
            line = next(a)    
            break
        elif special_string != c:
            c = line.strip()

In the special_string variable, whatever comes after info = can vary, so I am trying to put a wildcard operator as seen above. The only way I can get the function to run though is if I put in the exact string I want to search for, including everything after the equals sign as follows:

special_string = str('info         %d       info = more_stuff' %variable3)

How can I assign a wildcard operator to the rest of the string to make my function more robust?

Answer 1

Have you thought about using something like this? Based on your input, I'm assuming the following:

variable3 = 100000
special_string = str('info         %d       info = more_stuff' %variable3)

import re
pattern = re.compile('(info\s*\d+\s*info\s=)(.*)')
output = pattern.findall(special_string)
print(output[0][1])

Which would return:

more_stuff

Answer 2

If your special string always occurs at the start of a line, then you can use the below check (where special_string does not have the * at the end):

line.startswith(special_string)

Otherwise, please do look at the module re in the standard library for working with regular expressions.