trying to split a file by specifec word in python

June 7, 2022

i have a log file and i need to save the file with the lines that has a specific words.
‘begin’ and ‘end’
for example
this is the log:

19-3-2020 05:23:20.481  INFO    12  183 creating socket for traffic CONTROL module
19-3-2020 05:23:20.481  INFO    18  189 transaction 17336 begin
19-3-2020 05:23:20.622  INFO    17  194 creating mailslot for RSVP
19-3-2020 05:23:20.622  INFO    16  187 end transaction 17336
19-3-2020 05:23:20.622  INFO    13  193 transaction 17339 begin

this is what i need:

19-3-2020 05:23:20.481  INFO    18  189 transaction 17336 begin
19-3-2020 05:23:20.622  INFO    16  187 end transaction 17336
19-3-2020 05:23:20.622  INFO    13  193 transaction 17339 begin
19-3-2020 05:23:20.792  INFO    15  194 end transaction 17339

this is the what i write:

with open("exam.log", "r") as f:
    text = f.readlines()
END = 'end'
BEGIN = 'begin'
for val in text:
    if END in val:
        print(val)
    if BEGIN in val:
        print(val)

it give me what i want but i dont know what next. how to save it.

>Solution :

Write the lines to out.log instead of printing.

with open("exam.log", "r") as f:
    text = f.readlines()
END = 'end'
BEGIN = 'begin'

with open("out.log", "w") as f:
    for val in text:
        if END in val or BEGIN in val:
            f.writelines(val)