Getting strings in between two keywords from a file in python

Question

I tried to get some string between two keywords from a large text file with the following pattern searching each line by line and print it as well as store in another text file

'Event_WheelMonitorReleased' (253) 'Event_WheelMonitorPressed' (252) 'Event_WheelMonitorPressed' (252) 'Event_WheelMonitorPressed' (252)

Here I would like to extract only the strings inbetween EVENT()

Here I would say I need X_0_Gui_Menu_610_Menu_Status_System

I tried the following code

def get_navigated_pages():
    os.chdir('log_file')
    log_file = open('messages','r')
    data = log_file.read()
    navigated_pages = re.findall(r'EVENT(X(.*?)) ',data,re.DOTALL|re.MULTILINE)
    with open('navigated_page_file', 'w') as navigated_page_file:
         navigated_page_file.write(navigated_pages)

I expected the output in the text file to be something like this

X_0_Gui_Menu_650_Menu_Status_Version 
X_0_Gui_Menu_610_Menu_Status_System 
X_0_Gui_Menu_670_Menu_Status_Media

As mentioned above I would like to get the output only which is starting with X_0 and ignoring starting with other keywords

I just get ('Navigated pages: ', []) at the print statement and nothing at all in the text file — user89
– user89, Commented Nov 19, 2014 at 18:42
Not with the code you show here. You have a syntax error (missing a with before open) and multiple logic and spelling errors (navigated_page_file versus navigated_pages_file, giving a list object to write). In your comment you mention a print statement but show none in your code. You should show your actual code. — David Robinson
– David Robinson, Commented Nov 19, 2014 at 18:44

Kevin · Accepted Answer · 2014-11-19 18:58:05Z

1

Try escaping your outermost parentheses pair.

navigated_pages = re.findall(r'EVENT\(X(.*?)\) ',data,re.DOTALL|re.MULTILINE)

This appears to make it match properly, at least for my little sample input:

>>> s = "EVENT(X_HELLO) ... EVENT(X_HOW_ARE_YOU_DOING_TODAY)... EVENT(this one shouldn't appear because it doesn't start with X)"
>>> re.findall(r"EVENT\(X(.*?)\)", s)
['_HELLO', '_HOW_ARE_YOU_DOING_TODAY']

If you want the starting X too, you should nudge the inner parentheses to the left by one. Don't worry, I'm pretty sure the *? will still have the proper precedence.

>>> re.findall(r"EVENT\((X.*?)\)", s)
['X_HELLO', 'X_HOW_ARE_YOU_DOING_TODAY']

edited Nov 19, 2014 at 18:58

answered Nov 19, 2014 at 18:43

Kevin

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4 Comments

user89 Over a year ago

Hi, I forgot to add another info is that there are many other such EVENTS like EVENT(global_Z_Power_Popup) ..... with the following code it prints everything but I want only the ones which start with EVENT(X_ ...)

Kevin Over a year ago

@VenkateshPadmanabhan, ok, and my code does only show the ones starting with X. Or are you seeing something different?

user89 Over a year ago

I tried the second variation which you posted as I wanted the X keyword too. But it posts all the strings irrespective of the starting keyword. Everything which is inside EVENT()

user89 Over a year ago

It prints something like this

global_ImportActive_Popup', 'global_ListDelete_Confirm_Popup', 'global_OperationFailed_Popup', 'global_W_PlayPressInfo_Popup', 'global_WatchdogWelcomeNavigation', 'global_X_Locked_Cam_Info', 'global_Y_LockedDuringRecPrerec_Info', 'global_Z_Power_Popup', 'done', 'post', 'start', 'X_0_Gui_Menu_000_Menu_root', 'global_ExportActive_Popup', 'global_FileOverwrite_Confirm_Popup', 'global_Global_Reactions', 'global_ImportActive_Popup', 'global_ListDelete_Confirm_Popup', 'global_OperationFailed_Popup', 'global_W_PlayPressInfo_Popup', 'global_WatchdogWelcomeNavigation'

Padraic Cunningham · Accepted Answer · 2014-11-19 19:00:45Z

1

might get away with using split:

s = "Jan 01 08:11:13 AMIRA-134500021 user.notice gui-monitor[770]: ACTION:401b0836:8:EVENT(X_0_Gui_Menu_610_Menu_Status_System) 'Event_WheelMonitorReleased' (253)"
print(s.split("EVENT(")[1].rsplit(") ",1)[0])
X_0_Gui_Menu_610_Menu_Status_System

with open('message','r') as log_file:
    for line in log_file:
        print(line.split("EVENT(")[1].rsplit(") ",1)[0])

X_0_Gui_Menu_610_Menu_Status_System
X_0_Gui_Menu_610_Menu_Status_System
global_ExportActive_Popup
global_FileOverwrite_Confirm_Popup
global_Global_Reactions

To get only X_ lines:

with open('message','r') as log_file:
    for line in log_file:
        chk = line.split("EVENT(")[1].rsplit(") ",1)[0]
        if chk.startswith("X_"):
            print(chk)
X_0_Gui_Menu_610_Menu_Status_System
X_0_Gui_Menu_610_Menu_Status_System

If you are confident X_ only appears in the lines you want:

 for line in log_file:
    if "X_" in line:
        chk = line.split("EVENT(")[1].rsplit(") ",1)[0]
        print(chk)

edited Nov 19, 2014 at 19:00

answered Nov 19, 2014 at 18:45

Padraic Cunningham

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1 Comment

user89 Over a year ago

But I would like to store only the string which start with X_ I dont want other string which starts with other keywords.

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