pattern block expression matching

[Dan Sommers]

On Sat, 21 Jul 2018 17:37:00 +0100, MRAB wrote:

> On 2018-07-21 15:20, aldi.kraja at gmail.com wrote:
>> Hi,
>> I have a long text, which tells me which files from a database were downloaded and which ones failed. The pattern is as follows (at the end of this post). Wrote a tiny program, but still is raw. I want to find term "ERROR" and go 5 lines above and get the name with suffix XPT, in this first case DRXIFF_F.XPT, but it changes in other cases to some other name with suffix XPT. Thanks, Aldi
>> 
>> # reading errors from a file txt
>> import re
>> with open('nohup.out', 'r') as fh:
>>    lines = fh.readlines()
>>    for line in lines:
>>        m1 = re.search("XPT", line)
>>        m2 = re.search('ERROR', line)
>>        if m1:
>>          print(line)
>>        if m2:
>>          print(line)
>> 
> Firstly, you don't need regex for something has simple has checking for 
> the presence of a string.
> 
> Secondly, I think it's 4 lines above, not 5.
> 
> 'enumerate' comes in useful here:
> 
> with open('nohup.out', 'r') as fh:
>      lines = fh.readlines()
>      for i, line in enumerate(lines):
>          if 'ERROR' in line:
>              print(line)
>              print(lines[i - 4])

Where's awk when you need it?

import fileinput
for line in fileinput.fileinput('nohump.out'):
    if 'XPT' in line:
        line_containing_filename = line
    if 'ERROR' in line:
        print(line_containing_filename)

I think Aldi's original approach is pretty good.