SeqRecord

SeqRecord is a core data structure in Biopython that encapsulates a biological sequence along with its annotations and features. It is used to represent sequence records within the Biopython project and integrates with the SeqIO input/output framework.

A SeqRecord stores the sequence itself in the seq attribute (as a Seq object or string), and includes metadata fields such as id (primary identifier), name (short label), description (long text), dbxrefs (external database references), annotations (global metadata like source, taxonomy, date), features (a list of SeqFeature objects describing annotated regions), and letter_annotations (per-letter data such as quality scores). The features describe annotated regions such as genes or CDS, with locations and qualifiers that provide additional information.

SeqRecord works with SeqIO to read and write sequence data in formats such as FASTA, GenBank, EMBL, and FASTQ. Records can be created manually or produced by parsers, and then serialized to a chosen format via a writer. The object is mutable, so fields and annotations can be updated as data are processed.

Practical notes: SeqRecord provides a convenient container for sequence data and metadata, enabling downstream analysis and annotation workflows. The combination of sequence, features, and annotations makes it suitable for representing GenBank-style records as well as simple FASTA sequences, and it supports integration with feature-based analyses and database cross-references.

See also: Bio.Seq, Bio.SeqFeature, Bio.SeqIO.