[python]Regular expression

I have been avoiding regex for years as I find it very intimidating, however it seems this is a necessary skill to learn to build real things, I have real use cases to match for routes, access-lists and interfaces of routers and firewalls.

Here is a code snippet for the regex block, in this code snippet i have a collection of regex files for practice, the files are from the udemy instructor Sujith George on his course: The Complete Regular Expressions Course:Beginner to Advanced, he uses javascript to match the regex.

import re
from os.path import exists

path = "" # file path
pattern = "(fooa*bar)" # change the pattern as necessary
file = "regex01.txt" # change filename as necessary

# Check for file existence
if exists(path + file):
    with open(path + file, "r") as file:
        rows = file.read() # read the entire text file and store in rows object.
    regex = re.compile(pattern) # construct a regex object with regex.
    for row in rows.split(): # test on every row to find match
        if regex.search(row): # if a match is found print the row
            print(row)

Another code which uses list comprehension.

import re
from os.path import exists

path = "" # file path
pattern = "(fooa*bar)" # change the pattern as necessary
file = "regex01.txt" # change filename as necessary

# Check for file existence
if exists(path + file):
    with open(path + file, "r") as file:
        rows = file.read() # read the entire text file and store in rows object.
    regex = re.compile(pattern)
    print([row for row in rows.split() if regex.search(row)])

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