If the ID's are sorted, you could probably rig a binary search using seek. This'll be easier if the records have a constant length, but it's still possible for variable-length, just messier.
Otherwise you could stash them all in a dictionary (in memory) or anydbm (on disk) to get indexed access. On Mon, Mar 12, 2012 at 12:39 PM, Virgil Stokes <v...@it.uu.se> wrote: > I have a rather large ASCII file that is structured as follows > > header line > 9 nonblank lines with alphanumeric data > header line > 9 nonblank lines with alphanumeric data > ... > ... > ... > header line > 9 nonblank lines with alphanumeric data > EOF > > where, a data set contains 10 lines (header + 9 nonblank) and there can be > several thousand > data sets in a single file. In addition,* each header has a* *unique ID > code*. > > Is there a fast method for the retrieval of a data set from this large > file given its ID code? > > > -- > http://mail.python.org/mailman/listinfo/python-list > >
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