Mercurial > repos > nikhil-joshi > deseq_and_sam2counts
diff deseq/sam2counts_galaxy.py @ 0:d7f27b43b8ff draft
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author | nikhil-joshi |
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date | Thu, 05 Jul 2012 21:02:43 -0400 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/deseq/sam2counts_galaxy.py Thu Jul 05 21:02:43 2012 -0400 @@ -0,0 +1,209 @@ +#!/usr/bin/env python + +""" +count.py -- Take SAM files and output a table of counts with column +names that are the filenames, and rowname that are the reference +names. + +Author: Vince Buffalo +Email: vsbuffaloAAAAA@gmail.com (with poly-A tail removed) +""" + +VERSION = 0.91 + +import sys +import csv +from os import path +try: + import pysam +except ImportError: + sys.exit("pysam not installed; please install it\n") + +from optparse import OptionParser + +def SAM_file_to_counts(filename, bam=False, extra=False, use_all_references=True): + """ + Take SAM filename, and create a hash of mapped and unmapped reads; + keys are reference sequences, values are the counts of occurences. + + Also, a hash of qualities (either 0 or >0) of mapped reads + is output, which is handy for diagnostics. + """ + counts = dict() + unique = dict() + nonunique = dict() + mode = 'r' + if bam: + mode = 'rb' + sf = pysam.Samfile(filename, mode) + + if use_all_references: + # Make dictionary of all entries in header + for sn in sf.header['SQ']: + if extra: + unique[sn['SN']] = 0 + nonunique[sn['SN']] = 0 + counts[sn['SN']] = 0 + + for read in sf: + if not read.is_unmapped: + id_name = sf.getrname(read.rname) if read.rname != -1 else 0 + + if not use_all_references and not counts.get(id_name, False): + ## Only make keys based on aligning reads, make empty hash + if extra: + unique[id_name] = 0 + nonunique[id_name] = 0 + ## initiate entry; even if not mapped, record 0 count + counts[id_name] = counts.get(id_name, 0) + + + counts[id_name] = counts.get(id_name, 0) + 1 + + if extra: + if read.mapq == 0: + nonunique[id_name] = nonunique[id_name] + 1 + else: + unique[id_name] = unique[id_name] + 1 + + if extra: + return {'counts':counts, 'unique':unique, 'nonunique':nonunique} + + return {'counts':counts} + +def collapsed_nested_count_dict(counts_dict, all_ids, order=None): + """ + Takes a nested dictionary `counts_dict` and `all_ids`, which is + built with the `table_dict`. All files (first keys) in + `counts_dict` are made into columns with order specified by + `order`. + + Output is a dictionary with keys that are the id's (genes or + transcripts), with values that are ordered counts. A header will + be created on the first row from the ordered columns (extracted + from filenames). + """ + if order is None: + col_order = counts_dict.keys() + else: + col_order = order + + collapsed_dict = dict() + for i, filename in enumerate(col_order): + for id_name in all_ids: + if not collapsed_dict.get(id_name, False): + collapsed_dict[id_name] = list() + + # get counts and append + c = counts_dict[filename].get(id_name, 0) + collapsed_dict[id_name].append(c) + return {'table':collapsed_dict, 'header':col_order} + + +def counts_to_file(table_dict, outfilename, delimiter=',', labels=''): + """ + A function for its side-effect of writing `table_dict` (which + contains a table and header), to `outfilename` with the specified + `delimiter`. + """ + writer = csv.writer(open(outfilename, 'w'), delimiter=delimiter) + table = table_dict['table'] + if labels: + header = labels.split(',') + else: + header = table_dict['header'] + + header_row = True + for id_name, fields in table.items(): + if header_row: + row = ['id'] + header + writer.writerow(row) + header_row = False + + if id_name == 0: + continue + row = [id_name] + row.extend(fields) + writer.writerow(row) + +if __name__ == '__main__': + parser = OptionParser() + parser.add_option("-d", "--delimiter", dest="delimiter", + help="the delimiter (default: tab)", default='\t') + parser.add_option("-o", "--out-file", dest="out_file", + help="output filename (default: counts.txt)", + default='counts.txt', action="store", type="string") + parser.add_option("-u", "--extra-output", dest="extra_out", + help="output extra information on non-unique and unique mappers (default: False)", + default=False, action="store_true") + parser.add_option("-b", "--bam", dest="bam", + help="all input files are BAM (default: False)", + default=False, action="store_true") + parser.add_option("-r", "--use-all-references", dest="use_all_references", + help="Use all the references from the SAM header (default: True)", + default=True, action="store_false") + parser.add_option("-f", "--extra-out-files", dest="extra_out_files", + help="comma-delimited filenames of unique and non-unique output " + "(default: unique.txt,nonunique.txt)", + default='unique.txt,nonunique.txt', action="store", type="string") + parser.add_option("-v", "--verbose", dest="verbose", + help="enable verbose output") + parser.add_option("-l", "--columns-labels", dest="col_labels", help="comma-delimited label names for samples", action="store", type="string") + + (options, args) = parser.parse_args() + + if len(args) < 1: + parser.error("one or more SAM files as arguments required") + + file_counts = dict() + file_unique_counts = dict() + file_nonunique_counts = dict() + all_ids = list() + files = [path.basename(f) for f in args] + + if options.col_labels and len(files) != len(options.col_labels.split(',')): + parser.error("Number of sample names does not equal number of files") + + if len(set(files)) != len(set(args)): + parser.error("file args must have unique base names (i.e. no foo/bar joo/bar)") + + ## do a pre-run check that all files exist + for full_filename in args: + if not path.exists(full_filename): + parser.error("file '%s' does not exist" % full_filename) + + for full_filename in args: + filename = path.basename(full_filename) + ## read in SAM file, extract counts, and unpack counts + tmp = SAM_file_to_counts(full_filename, bam=options.bam, extra=options.extra_out, + use_all_references=options.use_all_references) + + if options.extra_out: + counts, unique, nonunique = tmp['counts'], tmp['unique'], tmp['nonunique'] + else: + counts = tmp['counts'] + + ## save counts, and unique/non-unique counts + file_counts[filename] = counts + + if options.extra_out: + file_unique_counts[filename] = unique + file_nonunique_counts[filename] = nonunique + + ## add all ids encountered in this in this file + all_ids.extend(file_counts[filename].keys()) + + ## Uniquify all_ids, and then take the nested file_counts + ## dictionary, collapse, and write to file. + all_ids = set(all_ids) + table_dict = collapsed_nested_count_dict(file_counts, all_ids, order=files) + counts_to_file(table_dict, options.out_file, delimiter=options.delimiter, labels=options.col_labels) + + if options.extra_out: + unique_fn, nonunique_fn = options.extra_out_files.split(',') + unique_table_dict = collapsed_nested_count_dict(file_unique_counts, all_ids, order=files) + nonunique_table_dict = collapsed_nested_count_dict(file_nonunique_counts, all_ids, order=files) + + counts_to_file(unique_table_dict, unique_fn, delimiter=options.delimiter) + counts_to_file(nonunique_table_dict, nonunique_fn, delimiter=options.delimiter) +