This is exactly the sort of stuff that Perl was designed to do, so it doesn't surprise me that it's faster.
One easy optimization in your Python code would be to precompile those regexes, so they aren't getting recompiled each time.
exists_re = re.compile(r'^(.*?) INFO.*Such a record already exists')
location_re = re.compile(r'^AwbLocation (.*?) insert into')
And then in your loop:
mprev = exists_re.search(currline)
and
mcurr = location_re.search(currline)
That by itself won't magically bring your Python script in line with your Perl script, but repeatedly calling re in a loop without compiling first is bad practice in Python.
