Using Python regex to check for string in file

Using Python regex to check for string in file

I'm using Python regex to check a log file that contains the output of the
Windows command tasklist for anything ending with .exe. This log file
contains output from multiple callings of tasklist. After I get a list of
strings with .exe in them, I want to write them out to a text file after
checking to see if that string already exists in the output file. Instead
of the desired output, it writes out duplicates of strings already present
in the text file. (svchost.exe shows up several times for example.) The
goal is to have a text file with a list of each unique process enumerated
by tasklist with no duplicates of processes already written in the file.
import re
file1 = open('taskinfo.txt', 'r')
strings = re.findall(r'.*.exe', file1.read())
file1.close()
file2 = open('exes.txt', 'w+')
for item in strings:
line_to_write = re.match(item, file2.read())
if line_to_write == None:
file2.write(item)
file2.write('\n')
else:
pass
I used print statements to debug and made sure than item is the desired
output.