Parsing by Line Data

[python1]

Having slight trouble conceptualizing a way to write this script. The 
problem is that I have a bunch of lines in a file, for example:

01A\n
02B\n
01A\n
02B\n
02C\n
01A\n
02B\n
.
.
.

The lines beginning with '01' are the 'header' records, whereas the 
lines beginning with '02' are detail. There can be several detail lines 
to a header.

I'm looking for a way to put the '01' and subsequent '02' line data into 
one list, and breaking into another list when the next '01' record is found.

How would you do this? I'm used to using 'readlines()' to pull the file 
data line by line, but in this case, determining the break-point will 
need to be done by reading the '01' from the line ahead. Would you need 
to read the whole file into a string and use a regex to break where a 
'\n01' is found?