#!/usr/bin/env python """test_align.py A script to test alignment stuff. Right now we've got tests for: o Reading and Writing clustal format o Reading and Writing fasta format o Converting between formats""" # standard library import os # biopython from Bio import Alphabet from Bio import Seq from Bio.Alphabet import IUPAC from Bio import Clustalw from Bio.Align.FormatConvert import FormatConverter from Bio.Align import AlignInfo from Bio.Fasta import FastaAlign from Bio.SubsMat import FreqTable from Bio.Align.Generic import Alignment #Very simple tests on an empty alignment alignment = Alignment(Alphabet.generic_alphabet) assert alignment.get_alignment_length() == 0 assert alignment.get_all_seqs() == [] del alignment #Basic tests on simple three string alignment alignment = Alignment(Alphabet.generic_alphabet) letters = "AbcDefGhiJklMnoPqrStuVwxYz" alignment.add_sequence("mixed", letters) alignment.add_sequence("lower", letters.lower()) alignment.add_sequence("upper", letters.upper()) assert alignment.get_alignment_length() == 26 assert len(alignment.get_all_seqs()) == 3 assert alignment.get_seq_by_num(0).tostring() == letters assert alignment.get_seq_by_num(1).tostring() == letters.lower() assert alignment.get_seq_by_num(2).tostring() == letters.upper() assert alignment.get_all_seqs()[0].description == "mixed" assert alignment.get_all_seqs()[1].description == "lower" assert alignment.get_all_seqs()[2].description == "upper" for (col, letter) in enumerate(letters) : assert alignment.get_column(col) == letter \ + letter.lower() \ + letter.upper() del alignment del letters print "testing reading and writing clustal format..." test_dir = os.path.join(os.getcwd(), 'Clustalw') test_names = ['opuntia.aln', 'cw02.aln'] test_files = [] for name in test_names: test_files.append(os.path.join(test_dir, name)) for test_file in test_files: # parse the alignment file and get an aligment object alignment = Clustalw.parse_file(test_file) # print the alignment back out print alignment alignment = Clustalw.parse_file(os.path.join(test_dir, test_names[0])) # test the base alignment stuff print 'all_seqs...' all_seqs = alignment.get_all_seqs() for seq_record in all_seqs: print 'description:', seq_record.description print 'seq:', seq_record.seq print 'length:', alignment.get_alignment_length() print 'Calculating summary information...' align_info = AlignInfo.SummaryInfo(alignment) consensus = align_info.dumb_consensus() print 'consensus:', consensus print 'Replacement dictionary' ks = align_info.replacement_dictionary(['N']).keys() ks.sort() for key in ks: print "%s : %s" % (key, align_info.replacement_dictionary(['N'])[key]) print 'position specific score matrix.' print 'with a supplied consensus sequence...' print align_info.pos_specific_score_matrix(consensus, ['N']) print 'defaulting to a consensus sequence...' print align_info.pos_specific_score_matrix(chars_to_ignore = ['N']) print 'with a selected sequence...' second_seq = alignment.get_seq_by_num(1) print align_info.pos_specific_score_matrix(second_seq, ['N']) print 'information content' print 'part of alignment:', align_info.information_content(5, 50, chars_to_ignore = ['N']) print 'entire alignment:', align_info.information_content( chars_to_ignore = ['N']) print 'relative information content' e_freq = {'G' : 0.25, 'C' : 0.25, 'A' : 0.25, 'T' : 0.25} e_freq_table = FreqTable.FreqTable(e_freq, FreqTable.FREQ, IUPAC.unambiguous_dna) print 'relative information:', align_info.information_content( e_freq_table = e_freq_table, chars_to_ignore = ['N']) print 'Column 1:', align_info.get_column(1) print 'IC for column 1:', align_info.ic_vector[1] print 'Column 7:', align_info.get_column(7) print 'IC for column 7:', align_info.ic_vector[7] print 'test print_info_content' AlignInfo.print_info_content(align_info) print "testing reading and writing fasta format..." to_parse = os.path.join(os.curdir, 'Fasta', 'fa01') alignment = FastaAlign.parse_file(to_parse, 'PROTEIN') # test the base alignment stuff print 'all_seqs...' all_seqs = alignment.get_all_seqs() for seq_record in all_seqs: print 'description:', seq_record.description print 'seq:', seq_record.seq print 'length:', alignment.get_alignment_length() align_info = AlignInfo.SummaryInfo(alignment) consensus = align_info.dumb_consensus(ambiguous = "X") print 'consensus:', consensus print alignment print "Test format conversion..." # parse the alignment file and get an aligment object alignment = Clustalw.parse_file(os.path.join(os.curdir, 'Clustalw', 'opuntia.aln')) converter = FormatConverter(alignment) fasta_align = converter.to_fasta() clustal_align = converter.to_clustal() print fasta_align print clustal_align """ # test to find a position in an original sequence given a # column position in an alignment print "Testing finding column positions..." alignment_info = ["GATC--CGATC--G", "GA--CCCG-TC--G", "GAT--CC--TC--G"] gapped_unambiguous = Alphabet.Gapped(IUPAC.unambiguous_dna) alignment = Alignment(gapped_unambiguous) for seq in alignment_info: alignment.add_sequence("Blah", seq) test_seq_1 = Seq.Seq("GATCCGATCG") orig_pos = alignment.original_sequence_pos(3, test_seq_1, 0) assert orig_pos == 3, "Got unexpected position: %s" % orig_pos orig_pos = alignment.original_sequence_pos(7, test_seq_1, 0) assert orig_pos == 5, "Got unexpected position: %s" % orig_pos orig_pos = alignment.original_sequence_pos(0, test_seq_1, 0) assert orig_pos == 0, "Got unexpected position: %s" % orig_pos orig_pos = alignment.original_sequence_pos(13, test_seq_1, 0) assert orig_pos == 9, "Got unexpected position: %s" % orig_pos try: orig_pos = alignment.original_sequence_pos(5, test_seq_1, 0) raise AssertionError("Did not fail with a junk position") except AssertionError: pass """