Building Time Based Bins

[MCD]

Hello, I'm new to python and this group and am trying to build some
bins and was wondering if any of you could kindly help me out. I'm a
bit lost on how to begin.

I have some text files that have a time filed along with 2 other fields
formatted like this >>

1231 23 56
1232 25 79
1234 26 88
1235 22 34
1237 31 85
1239 35 94

This goes on throughout a 12hr. period. I'd like to be able to place
the low and high values of the additional fields in a single line
divided into 5min intervals. So it would look something like this >>

1235 22 88
1240 31 94

I hope that makes sense. Should I be using a module like numarray for
this, or is it possible to just use the native functions? Any ideas
would help me very much.

Thank you - Marcus