remove last 76 letters from string [sorry, errata]

Jan Kaliszewski zuo at
Thu Aug 6 02:24:22 CEST 2009

Dnia 06-08-2009 o 01:54:46 PeroMHC <macmanes at> wrote:

> This snippet represents 3 individual DNA sequences. Each sequences is
> identified by the line starting with >
> The complete file has about 10 million individual sequences.
> A simple enough problem, I want to read in this data, and cut out the
> last 76 letters (nucleotides) from each individual sequence and send
> them to a new txt file with a similar format.

If I understand correctly you want sth like this:

with open(path_to_the_input_file) as fasta:
       with open(path_to_the_output_file) as nucleotides:
	for seq in fasta:
               print >>nucleotides, '> foo bar length=76'
               print >>nucleotides, seq[-76]


Jan Kaliszewski (zuo) <zuo at>

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