Program workflow:

1. Open "asigra_backup.txt" file and read each line
2. Search for the exact string: "Errors: " {any value ranging from 1 - 100}. e.g "Errors: 12"
3. When a match is found, open a separate .txt file in write&append mode
4. Write the match found. Example: "Errors: 4"
5. In addition to above write, append the next 4 lines below the match found in step 3; as that is additional log information What I've done:
6. Tested a regular expressions that matches with my sample data on regex101.com
7. Used list comprehension to find all matches in my test file Where I need help (please):
8. Figuring out how to append additional 4 lines of log information below each match string found

CURRENT CODE:

result = [line.split("\n")[0] for line in open('asigra_backup.txt') if re.match('^Errors:\s([1-9]|[1-9][0-9]|100)',line)]

print(result)

CURRENT OUTPUT:

['Errors: 1', 'Errors: 128']

DESIRED OUTPUT:

Errors: 1
Pasta
Fish 
Dog
Doctonr
Errors: 128
Lemon
Seasoned
Rhinon
Goat

SAMPLE .TXT FILE

Errors: 1
Pasta
Fish 
Dog
Doctonr
Errors: 128
Lemon
Seasoned
Rhinon
Goat
Errors: 0 
Rhinon
Cat 
Dog
Fish 

CodePudding user response：

Using better regex and re.findall can make it easier. In the following regex, all Errors: and 4 following lines are detected.

import re
regex_matches = re.findall('(?:[\r\n] |^)((Errors:\s*([1-9][0-9]?|100))(?:[\r\n\s\t] .*){4})', open('asigra_backup.txt', 'r').read())
open('separate.txt', 'a').write('\n'   '\n'.join([i[0] for i in regex_matches]))

To access error numbers or error lines following lines can use:

error_rows = [i[1] for i in regex_matches]
error_numbers = [i[2] for i in regex_matches]
print(error_rows)
print(error_numbers)

CodePudding user response：

I wrote a code which prints the output as requested. The code will work when Errors: 1 line is added as last line. See the text I have parsed:

data_to_parse = """
Errors: 56
Pasta
Fish 
Dog
Doctonr
Errors: 0
Lemon
Seasoned
Rhinon
Goat
Errors: 45
Rhinon
Cat 
Dog
Fish
Errors: 34
Rhinon
Cat 
Dog
Fish1
Errors: 1
"""

See the code which gives the desired output without using regex. Indices have been used to get desired data.

lines = data_to_parse.splitlines()

errors_indices = []

i = 0
k = 0

for line in lines: # where Errors: are located are found in saved in list errors_indices. 
    if 'Errors:' in line:
        errors_indices.append(i)
    i = i 1

#counter = False

while k < len(errors_indices):
    counter = False # It is needed to find the indices when Errors: 0 is hit. 
    for j in range(errors_indices[k-1], errors_indices[k]):
        if 'Errors:' in lines[j]:
            lines2 = lines[j].split(':')
            lines2_val = lines2[1].strip()
            if int(lines2_val) != 0:
                print(lines[j])
            if int(lines2_val) == 0:
                counter = True
            
        elif 'Errors:' not in lines[j] and counter == False:
            print(lines[j])
    k=k 1

I have tried a few times to see if the code is working properly. It looks it gives the requested output properly. See the output when the code is run as: