Search text file for a time range - python

Question

I am playing around with python and I am trying to figure out a way to search a text file for a specific word within a time range. The file has time stamps, however since the file is a text file everything is a string.

Text file contains the below:

17:14:26.442 words words words words words

17:15:32.533 words words words words words

17:16:26.442 words words words words words

17:17:32.533 words words words words words

17:18:26.442 words words words words words

17:19:32.533 words words words words words

17:20:26.442 words words words words words

17:21:32.533 words words words words words

What I want to do is search for a word in a time frame and get back only that line that has word between 17:17:32.533 and 17:20:26.442. However, since its a text document and everything is a string I cannot use the range option. Does anyone have some suggestions on how I can do this?

do you have to do it only once per file, or many times? and do you want to perform a word only search or a substring search? — Jean-François Fabre, Aug 12 '16 at 19:48
If you have a lot of times to check against the file, you should sort the data by time and then use bisect to get log n lookups — Padraic Cunningham, Aug 12 '16 at 19:49

score 1 · Accepted Answer · answered Aug 12 '16 at 19:44

1

Use the datetime module to parse and convert the timestamp strings to datetime object and then you can use the comparison in order to check only the lines that fall in that time range.

from datetime import datetime as dt

start = dt.strptime('17:17:32.533','%H:%M:%S.%f')
end = dt.strptime('17:20:26.442','%H:%M:%S.%f')
word_to_search = 'word'
with open('sample.txt', 'r') as f:
    for line in f:
        ts=dt.strptime(line.split()[0],'%H:%M:%S.%f')
        if ts>start and ts<end:
            if word_to_search in line:
                print line

answered Aug 12 '16 at 19:44

Wajahat

1,593
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naïve question: why not using `time.strptime` ? – Jean-François Fabre Aug 12 '16 at 19:48
I think it does not work as I read the first answer to this question http://stackoverflow.com/questions/698223/how-can-i-parse-a-time-string-containing-milliseconds-in-it-with-python – Wajahat Aug 12 '16 at 19:50
Actually it might just work, the `struct_time` may not contain microseconds but if there are no duplicate timestamps (removing milliseconds) then it will work fine. – Wajahat Aug 12 '16 at 20:06
Ok, better safe than sorry, I'll use `datetime` from now on. thanks. – Jean-François Fabre Aug 12 '16 at 20:15

Tim Fuchs · Answer 2 · 2016-08-12T19:54:15.250

0

If the timestamps are exactly in the format you describe (HH:MM:SS.sss), then you can compare directly:

start = '17:17:32.533'
end = '17:20:26.442'
with open(filename, 'r') as f:
    for line in f:
        if line[:12] >= start and line[:12] <= end:
            print(line)

If this doesn't work, because e.g. 01:01:01.000 is outputted as 1:1:1.0, you have to parse the timestamp first. For example:

import datetime
start = datetime.time(17, 17, 32, 533)
end = datetime.time(17, 20, 26, 442)
with open(filename, 'r') as f:
    for line in f:
        timestamp, words = line.split(None, 1)
        time = datetime.strptime(timestamp, "%H:%M:%S.%f").time()
        if time >= start and time <= end:
            print(words)

edited Aug 12 '16 at 19:54

answered Aug 12 '16 at 19:33

Tim Fuchs

1,171
6
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split takes no keyword args, you want `line.split(None,1)` – Padraic Cunningham Aug 12 '16 at 19:50
Ah, yes, sorry, wrong python version. In Python3 it does. – Tim Fuchs Aug 12 '16 at 19:52
Thanks TIm Fuchs, I will test and play around with it some and post here what I find. I appreciate your detailed and quick response! I'm on python Version 2.7 – user6534872 Aug 12 '16 at 19:52

Search text file for a time range - python

2 Answers2