class skbio.core.alignment.Alignment(seqs, validate=False)[source]

Class for storing alignments of biological sequences.

The Alignment class adds convenience methods to the SequenceCollection class to make it easy to work with alignments of biological sequences.


By definition, all of the sequences in an alignment must be of the same length. For this reason, an alignment can be thought of as a matrix of sequences (rows) by positions (columns).


__contains__(id) The in operator.
__eq__(other) The equality operator.
__getitem__(index) The indexing operator.
__iter__() The iter operator.
__len__() The len operator.
__ne__(other) The inequality operator.
__repr__() The repr method.
__reversed__() The reversed method.
__str__() The str method.
degap() Return a new SequenceCollection with all gap characters removed.
distances() Compute distances between all pairs of sequences
distribution_stats([center_f, spread_f]) Return sequence count, and center and spread of sequence lengths
from_fasta_records(fasta_records, ...[, ...]) Initialize a SequenceCollection object
get_seq(id) Return a sequence from the SequenceCollection by its id.
ids() Returns the BiologicalSequence ids
int_map([prefix]) Create an integer-based mapping of sequence ids
is_empty() Return True if the SequenceCollection is empty
is_valid() Return True if the Alignment is valid
iter_positions([constructor]) Generator of Alignment positions (i.e., columns)
iteritems() Generator of id, sequence tuples
k_word_frequencies(k[, overlapping, constructor]) Return frequencies of length k words for sequences in Alignment
lower() Converts all sequences to lowercase
majority_consensus([constructor]) Return the majority consensus sequence for the Alignment
omit_gap_positions(maximum_gap_frequency) Returns Alignment with positions filtered based on gap frequency
omit_gap_sequences(maximum_gap_frequency) Returns Alignment with sequences filtered based on gap frequency
position_counters() Return collection.Counter object for positions in Alignment
position_entropies([base, ...]) Return Shannon entropy of positions in Alignment
position_frequencies() Return frequencies of characters for positions in Alignment
sequence_count() Return the count of sequences in the SequenceCollection
sequence_length() Return the number of positions in Alignment
sequence_lengths() Return lengths of the sequences in the SequenceCollection
subalignment([seqs_to_keep, ...]) Returns new Alignment that is a subset of the current Alignment
toFasta() Return fasta-formatted string representing the SequenceCollection
to_fasta() Return fasta-formatted string representing the SequenceCollection
to_phylip([map_labels, label_prefix]) Return phylip-formatted string representing the SequenceCollection
upper() Converts all sequences to uppercase