Regex on list element in for loop

Question

I have a script that searches through config files and finds all matches of strings from another list as follows:

dstn_dir = "C:/xxxxxx/foobar"
dst_list =[]
files = [fn for fn in os.listdir(dstn_dir)if fn.endswith('txt')]
dst_list = []
for file in files:
    parse = CiscoConfParse(dstn_dir+'/'+file)
    for sfarm in search_str:
        int_objs = parse.find_all_children(sfarm)
        if len(int_objs) > 0:
            dst_list.append(["\n","#" *40,file + " " + sfarm,"#" *40])
            dst_list.append(int_objs)

I need to change this part of the code:

 for sfarm in search_str:
            int_objs = parse.find_all_children(sfarm)

search_str is a list containing strings similar to ['xrout:55','old:23'] and many others.

So it will only find entries that end with the string from the list I am iterating through in sfarm. My understanding is that this would require my to use re and match on something like sfarm$ but Im not sure on how to do this as part of the loop.

Am I correct in saying that sfarm is an iterable? If so I need to know how to regex on an iterable object in this context.

You forgot to include the definition of search_str, so it's hard to say what sfarm is. In other words, see "How to create a Minimal, Complete, and Verifiable example". — Ilja Everilä
– Ilja Everilä, Commented Aug 26, 2016 at 8:16
search_str is the iterable and sfarm is a normal element (that may be iterable too) of your list on which you can use regex — Julien
– Julien, Commented Aug 26, 2016 at 8:17
IIja Everila and me wants to know how search_str will populated and from where? More, it will be good if you can add sample data that can be search_str. — Dinesh Pundkar
– Dinesh Pundkar, Commented Aug 26, 2016 at 8:19
if you only wants to check that a string ends with a substring, you do not need regular expression, the endswith method of string should be enough: docs.python.org/2/library/… — Tryph
– Tryph, Commented Aug 26, 2016 at 8:21
As @DineshPundkar pointed out you could simplify greatly your file handling with either the glob module or if using python 3 pathlib module's globbing features. — Ilja Everilä
– Ilja Everilä, Commented Aug 26, 2016 at 8:41

Ilja Everilä · Accepted Answer · 2016-08-26 08:32:34Z

2

Strings in python are iterable, so sfarm is an iterable, but that has little meaning in this case. From reading what CiscoConfParse.find_all_children() does, it is apparent that your sfarm is the linespec, which is a regular expression string. You do not need to explicitly use the re module here; just pass sfarm concatenated with '$':

search_string = ['xrout:55','old:23']
...
for sfarm in search_str:
    int_objs = parse.find_all_children(sfarm + '$')  # one of many ways to concat
...

answered Aug 26, 2016 at 8:32

Ilja Everilä

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1 Comment

nipy Over a year ago

Thanks for the lesson and simple effective solution. I have accepted this as the answer

Dinesh Pundkar · Accepted Answer · 2016-08-26 08:52:36Z

1

Please check this code. Used glob module to get all "*.txt" files in folder.

Please check here for more info on glob module.

import glob
import re
dst_list = []
search_str = ['xrout:55','old:23']
for file_name in glob.glob(r'C:/Users/dinesh_pundkar\Desktop/*.txt'):
    with open(file_name,'r') as f:
        text = f.read()
        for sfarm in search_str:
            regex = re.compile('%s$'%sfarm)
            int_objs = regex.findall(text)
            if len(int_objs) > 0:
                dst_list.append(["\n","#" *40,file_name + " " + sfarm,"#" *40])
                dst_list.append(int_objs)
print dst_list

Output:

 C:\Users\dinesh_pundkar\Desktop>python a.py
[['\n', '########################################', 'C:/Users/dinesh_pundkar\\De
sktop\\out.txt old:23', '########################################'], ['old:23']]

C:\Users\dinesh_pundkar\Desktop>

edited Aug 26, 2016 at 8:52

answered Aug 26, 2016 at 8:35

Dinesh Pundkar

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1 Comment

nipy Over a year ago

Marking this answer up as per suggestion to use glob, thanks

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