, header=None, seq_type=None)[source]

Get a sequence from a FastaFile instance.

The type of sequence is guessed from the sequence string: First, a conversion into a NucleotideSequence and second a conversion into a ProteinSequence is tried.


The FastaFile to be accessed.

headerstr, optional

The header to get the sequence from. By default, the first sequence of the file is returned.

seq_typeClass, optional

The Sequence subclass contained in the file. If not set, biotite will attempt to automatically detect whether a nucleotide or protein sequence is present.

sequenceNucleotideSequence or ProteinSequence

The requested sequence in the FastaFile. NucleotideSequence if the sequence string fits the corresponding alphabet, ProteinSequence otherwise.


If the sequence data can be neither converted into a NucleotideSequence nor a ProteinSequence.