import re, sys

with open('temp.log') as f:
   lines = f.readlines()

with open('output.txt') as o:

    data = []
    for line in lines:
       if 'date' in sys.argv:
           try:
              date = re.match(r'date{2} w+ date{2}', line).group()
              row.append(date)
           except:
              date = 'date'
       if 'agent' in sys.argv:
           try:
              agent = re.search(r'agent:s(.*?),', line).group()
              row.append(agent)
           except:
              agent = 'agent:'
       if 'err' in sys.argv:
           try:
              errID = re.search(r'ErrIdText:s(.*?),', line).group()
              row.append(errID)
           except:
              errID = 'ErrIdText:'
       if 'clear' in sys.argv:
           try:
              clear = re.search(r'clearedID:s(.*?))', line).group()
              row.append(clear)
           except:
              clear = 'clearedID:'

       row = []
       data.append(row)

     for row in data:
        lines = o.writelines(row)
        print(row)

     o.close()

python export.py agent chassis

['agent: 12367a12,', 'chassis:12367a12,']
['agent: 12368a15,', 'chassis:12368a15,']