Read in file - change contents - write out to same file

Question

I have to read in a file, change a sections of the text here and there, and then write out to the same file.

Currently I do:

f = open(file)
file_str          


        

Answer 1

If you work line by line you can use fileinput with inplace mode

import fileinput

for line in fileinput.input(mifile, inplace=1):
    print process(line)

if you need to process all the text at once, then your code can be optimized a bit using with that takes care of closing the file:

with open(myfile) as f:
    file_str = f.read()
#
do_actions_on_file_str
#
with open(myfile, 'w') as f:
    f.write(file_str)