Extract Values between two strings in a text file using python

[helloR]

Lets say I have a Text file (input_file.txt , file size is ~10GB ).

Now I need to write a Python code which will read the text file and copy the contents between Start and end to another file.

I wrote the following code.

import re  

with open(r'C:\Python27\log\master_input.txt', 'r') as infile, open(r'C:\Python27\log\output', 'w') as outfile:  
   copy = False  
   for line in infile:  
      if re.match("Jun  6 17:58:16(.*)", line):  
         copy = True  
      elif re.match("Jun  6 17:58:31(.*)", line):  
         copy = False  
      elif copy:  
         outfile.write(line)

I'm not getting the desired output as expected:

Output of the code ( output_of_my_co de.txt ):

Expected output is ( Expected_output .txt ):

Pls help me here to do it in best way

[bvdet]

To achieve the output you need, use re to determine an integer representing the seconds and compare to the lower and upper boundaries. Here's an example:

import re

data = """Jun  6 17:58:13 other strings
Jun  6 17:58:13 other strings
Jun  6 17:58:14 other strings
Jun  6 17:58:14 other strings
Jun  6 17:58:15 other strings
Jun  6 17:58:15 other strings
Jun  6 17:58:15 other strings
Jun  6 17:58:15 other strings
Jun  6 17:58:16 other strings
Jun  6 17:58:16 other strings
Jun  6 17:58:16 other strings
Jun  6 17:58:16 other strings
Jun  6 17:58:16 other strings
Jun  6 17:58:16 other strings
Jun  6 17:58:17 other strings
Jun  6 17:58:17 other strings
Jun  6 17:58:17 other strings
Jun  6 17:58:17 other strings
Jun  6 17:58:18 other strings
Jun  6 17:58:18 other strings
Jun  6 17:58:18 other strings
Jun  6 17:58:18 other strings
Jun  6 17:58:18 other strings
Jun  6 17:58:19 other strings
Jun  6 17:58:19 other strings
Jun  6 17:58:20 other strings
Jun  6 17:58:20 other strings
Jun  6 17:58:21 other strings
Jun  6 17:58:21 other strings
Jun  6 17:58:21 other strings
Jun  6 17:58:21 other strings
Jun  6 17:58:22 other strings
Jun  6 17:58:23 other strings
Jun  6 17:58:24 other strings
Jun  6 17:58:27 other strings
Jun  6 17:58:28 other strings
Jun  6 17:58:28 other strings
Jun  6 17:58:29 other strings
Jun  6 17:58:29 other strings
Jun  6 17:58:29 other strings
Jun  6 17:58:29 other strings
Jun  6 17:58:30 other strings
Jun  6 17:58:31 other strings
Jun  6 17:58:31 other strings
Jun  6 17:58:32 other strings
Jun  6 17:58:33 other strings
Jun  6 17:58:33 other strings
Jun  6 17:58:33 other strings
Jun  6 17:58:33 other strings"""

patt = re.compile("Jun  6 17:58:(\d+?) (.*)")
upper = 31
lower = 16

for line in data.split("\n"):
    m = patt.match(line)
    if m:
        i = int(m.group(1))
        if i >= lower and i <= upper:
            print line

[helloR]

@bvdet: Thanks for the solution. Here i do not know the upper and lower value... How did you get those values...

[bvdet]

You knew the upper and lower values in your original post. How did you know them? If you are dealing with dates and times instead of strictly formatted data, look into using the time and datetime modules. Example of creating a datetime object from the date/time string:

>>> datetime.datetime.strptime("Jun  6 17:58:13", "%b  %d %H:%M:%S")
datetime.datetime(1900, 6, 6, 17, 58, 13)
>>>

From there you can create timedelta objects:

>>> d1 = datetime.datetime.strptime("Jun  6 17:58:13", "%b  %d %H:%M:%S")
>>> d2 = datetime.datetime.strptime("Jun  7 12:55:48", "%b  %d %H:%M:%S")
>>> d1-d2
datetime.timedelta(-1, 18145)
>>> d2-d1
datetime.timedelta(0, 68255)
>>> dt1 = d1-d2
>>> dt1.days
-1
>>> dt1.total_seconds()
-68255.0
>>> dt2 = d2-d1
>>> dt2.days
0
>>> dt2.total_seconds()
68255.0
>>>