如何在文件中查找特定字符串？

Question

This is a script that I have written to find all the lines with usb in it. However, the problem is that if also returns lines if they have words such as usbcore as well. I am interested in lines that contain only the words usb.

#!/usr/bin/python

import sys

logFile = open(sys.argv[1])

print("Printing all lines with USB in it...")

for line in logFile.readlines():
    if line.lower().find('usb') != -1:
        print(line)

print('Done!')

Answer 1

You can try to find the word ' usb ' with spaces:

import sys

logFile = open(sys.argv[1])

print("Printing all lines with USB in it...")

for line in logFile.readlines():
    if line.lower().find(' usb ') != -1:
        print(line)

print('Done!')

• Example:

   a = ' i have usbbox ' b = ' i have usb ' a.find('usb') #.= -1 a,find(' usb ') # = -1. bcs it doesnt contain the word 'usb' only b,find(' usb ') # != -1 , it contains it

Answer 2

Here`sa one-liner:

with open(sys.arg[1]) as f: 
    print(''.join([l for l in f.readlines() if ' ubs ' in l.lower()])