Editing Biopython (section)

=== Sequences ===
A core concept in Biopython is the biological sequence, and this is represented by the <code>Seq</code> class.<ref name="Tutorial">{{Citation |last1=Chang |first1=Jeff |last2=Chapman |first2=Brad |last3=Friedberg |first3=Iddo |last4=Hamelryck |first4=Thomas |last5=de Hoon |first5=Michiel |last6=Cock |first6=Peter |last7=Antao |first7=Tiago |last8=Talevich |first8=Eric |last9=Wilczynski |first9=Bartek  |title=Biopython Tutorial and Cookbook |url=http://biopython.org/DIST/docs/tutorial/Tutorial.html |date=29 May 2014 |accessdate=28 August 2014}}</ref>  A Biopython <code>Seq</code> object is similar to a Python string in many respects: it supports the Python slice notation, can be concatenated with other sequences and is immutable. In addition, it includes sequence-specific methods and specifies the particular biological alphabet used.

<syntaxhighlight lang="pycon">
>>> # This script creates a DNA sequence and performs some typical manipulations
>>> from Bio.Seq import Seq
>>> dna_sequence = Seq("AGGCTTCTCGTA", IUPAC.unambiguous_dna)
>>> dna_sequence
Seq('AGGCTTCTCGTA', IUPACUnambiguousDNA())
>>> dna_sequence[2:7]
Seq('GCTTC', IUPACUnambiguousDNA())
>>> dna_sequence.reverse_complement()
Seq('TACGAGAAGCCT', IUPACUnambiguousDNA())
>>> rna_sequence = dna_sequence.transcribe()
>>> rna_sequence
Seq('AGGCUUCUCGUA', IUPACUnambiguousRNA())
>>> rna_sequence.translate()
Seq('RLLV', IUPACProtein())
</syntaxhighlight>