# HG changeset patch # User jjohnson # Date 1361205170 18000 # Node ID 3890f8ba0e4d37393d46c4ab445ca0ef6af7313c Uploaded diff -r 000000000000 -r 3890f8ba0e4d pileup_to_vcf.py --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/pileup_to_vcf.py Mon Feb 18 11:32:50 2013 -0500 @@ -0,0 +1,263 @@ +#!/usr/bin/env python +""" +# +#------------------------------------------------------------------------------ +# University of Minnesota +# Copyright 2012, Regents of the University of Minnesota +#------------------------------------------------------------------------------ +# Author: +# +# James E Johnson +# Jesse Erdmann +# +#------------------------------------------------------------------------------ +""" + +""" +Generate a VCF file from a samtools pileup +filtering on read coverage, base call quality, and allele frequency + +Pileup Format +http://samtools.sourceforge.net/pileup.shtml +Columns: +chromosome, 1-based coordinate, reference base, the number of reads covering the site, read bases, base qualities + +VCF Format +http://www.1000genomes.org/wiki/Analysis/Variant%20Call%20Format/vcf-variant-call-format-version-41 +The header line names the 8 fixed, mandatory columns. These columns are as follows: +CHROM POS ID REF ALT QUAL FILTER INFO +""" + +import sys,re,os.path +import optparse +from optparse import OptionParser + +vcf_header = """\ +##fileformat=VCFv4.0 +##source=pileup_to_vcf.pyV1.0 +##INFO= +##INFO= +##FILTER= +##FILTER= +#CHROM POS ID REF ALT QUAL FILTER INFO\ +""" + +def __main__(): + #Parse Command Line + parser = optparse.OptionParser() + # files + parser.add_option( '-i', '--input', dest='input', help='The input pileup file (else read from stdin)' ) + parser.add_option( '-o', '--output', dest='output', help='The output vcf file (else write to stdout)' ) + # filters + parser.add_option( '-c', '--min_coverage', type='int', default='0', dest='min_coverage', help='The minimum read coverage depth to report a variant [default 0]' ) + parser.add_option( '-r', '--report_depth', type='choice', choices=['all','ref','qual'], default='ref', dest='report_depth', help='Coverage depth as: ref - reads covercovering base, all - reads spanning base, qual - reads with base call above min_base_quality' ) + parser.add_option( '-b', '--min_base_quality', type='int', default='0', dest='min_base_quality', help='The minimum base quality for a base call to be counted' ) + parser.add_option( '-f', '--min_allele_freq', type='float', default='.5', dest='min_allele_freq', help='The minimum frequency of an allele for it to be reported (default .5)' ) + parser.add_option( '-m', '--allow_multiples', action="store_true", dest='allow_multiples', default=False, help='Allow multiple alleles to be reported' ) + parser.add_option( '-s', '--snps_only', action="store_true", dest='snps_only', default=False, help='Only report SNPs, not indels' ) + # select columns + parser.add_option( '-C', '--chrom_col', type='int', default='1', dest='chrom_col', help='The ordinal position (starting with 1) of the chromosome column' ) + parser.add_option( '-P', '--pos_col', type='int', default='2', dest='pos_col', help='The ordinal position (starting with 1) of the position column' ) + parser.add_option( '-R', '--ref_col', type='int', default='3', dest='ref_col', help='The ordinal position (starting with 1) of the reference base column' ) + parser.add_option( '-D', '--coverage_col', type='int', default='4', dest='coverage_col', help='The ordinal position (starting with 1) of the read coverage depth column' ) + parser.add_option( '-B', '--base_call_col', type='int', default='5', dest='base_call_col', help='The ordinal position (starting with 1) of the base call column' ) + parser.add_option( '-Q', '--base_qual_col', type='int', default='6', dest='base_qual_col', help='The ordinal position (starting with 1) of the base quality column' ) + # debug + parser.add_option( '-d', '--debug', action="store_true", dest='debug', default=False, help='Print Debug messages' ) + # + (options, args) = parser.parse_args() + + debug = options.debug if options.debug else False + + #Coverage must have at least a total depth of min_coverage to be considered + min_coverage = options.min_coverage + #Count depth as: ref - reads covercovering base, all - reads spanning base, qual - reads with base call above min_base_quality + dp_as = options.report_depth + #Base qualities must be at least the min_base_quality value to be counted + min_base_quality = options.min_base_quality + #Coverage must be more than this pct in support of the variant, e.g. variant support / total coverage > min_allele_freq + min_allele_freq = options.min_allele_freq + #Allow multiple variants to be reported for a position, min_allele_freq must be less than 0.5 for this to have effect. + allow_multiples = options.allow_multiples + # Whether to report indels + report_indels = not options.snps_only + + # Check for 1-based column options, and subtract 1 for python array index + #Which column (count starting with 1) contains the chromosome (Default assumes 6-col pileup or 12-col filtered pileup) + chrom_col = options.chrom_col - 1 + #Which column (count starting with 1) contains the position (Default assumes 6-col pileup or 12-col filtered pileup) + pos_col = options.pos_col - 1 + #Which column (count starting with 1) contains the reference base (Default assumes 6-col pileup or 12-col filtered pileup) + ref_col = options.ref_col - 1 + #Which column (count starting with 1) contains the total coverage for the position (Default assumes 6-col pileup or 12-col filtered pileup) + coverage_col = options.coverage_col - 1 + #Which column (count starting with 1) contains the base calls for the position (Default assumes 6-col pileup or 12-col filtered pileup) + base_call_col = options.base_call_col - 1 + #Which column (count starting with 1) contains the base call qualities for the position (Default assumes 6-col pileup or 12-col filtered pileup) + base_qual_col = options.base_qual_col - 1 + + # pileup input + if options.input != None: + try: + inputPath = os.path.abspath(options.input) + inputFile = open(inputPath, 'r') + except Exception, e: + print >> sys.stderr, "failed: %s" % e + exit(2) + else: + inputFile = sys.stdin + # vcf output + if options.output != None: + try: + outputPath = os.path.abspath(options.output) + outputFile = open(outputPath, 'w') + except Exception, e: + print >> sys.stderr, "failed: %s" % e + exit(3) + else: + outputFile = sys.stdout + + indel_len_pattern = '([1-9][0-9]*)' + ref_skip_pattern = '[<>]' + + SAF_header = "SAF"; + + print >> outputFile, vcf_header % (min_coverage,min_allele_freq,min_base_quality) + + try: + for linenum,line in enumerate(inputFile): + if debug: print >> sys.stderr, "%5d:\t%s" % (linenum,line) + fields = line.split('\t') + adp = int(fields[coverage_col]) # count of all reads spanning ref base + # Quick check for coverage + if adp < min_coverage : + continue + bases = fields[base_call_col] + if dp_as != 'all' : + m = re.findall(ref_skip_pattern,bases) + # Quick check for coverage, pileup coverage - reference skips + if adp -len(m) < min_coverage: + continue + quals = fields[base_qual_col] + chrom = fields[chrom_col] + pos = int(fields[pos_col]) + ref = fields[ref_col] + deletions = dict() + max_deletion = 0 + insertions = dict() + snps = {'A':0,'C':0,'G':0,'T':0,'N':0} + bi = 0 # bases index + qi = 0 # quals index + rdp = 0 # read coverage depth + qdp = 0 # read coverage depth with base call quality passing minimum + variants = dict() # variant -> count + while bi < len(bases): + base = bases[bi] + if debug: print >> sys.stderr, "%3d\t%s\t%3d\t%s %3d" % (bi,base,qi,quals[qi],ord(quals[qi]) - 33) + bi += 1 + if base in '<>' : #reference skip (between paired reads) + pass; + elif base in '.,' : # match reference on forward/reverse strand + rdp += 1 + qual = ord(quals[qi]) -33 + qi += 1 + # count match + if qual >= min_base_quality: + qdp += 1 + elif base in 'ACGTNacgtn' : # SNP on forward/reverse strand + rdp += 1 + qual = ord(quals[qi]) -33 + qi += 1 + # record snp variant + if qual >= min_base_quality: + qdp += 1 + snps[base.upper()] += 1 + elif base in '+-' : # indel + rdp += 1 + qdp += 1 # no related quality score, so count it + m = re.match(indel_len_pattern,bases[bi:]) + indel_len_str = m.group(0) # get the indel len string + bi += len(indel_len_str) # increment the index by the len of the len string + indel_len = int(indel_len_str) + indel = bases[bi:bi+indel_len].upper() # get the indel bases + bi += indel_len # increment the index by the len of the indel + if base == '+': + # record insertion variant + if indel in insertions: + insertions[indel] += 1 + else: + insertions[indel] = 1 + elif base == '-': + # record deletion variant + max_deletion = max(indel_len,max_deletion) + if indel in deletions: + deletions[indel] += 1 + else: + deletions[indel] = 1 + elif base == '^' : #start of read (followed by read quality char) + read_mapping_qual = ord(bases[bi]) - 33 + bi += 1 + elif base == '$' : #end of read + pass # no associated quality in either bases or quals + dp = rdp if dp_as == 'ref' else qdp if dp_as == 'qual' else adp + if debug: print >> sys.stderr, "snps: %s\tins: %s\tdel: %s" % (snps,insertions,deletions) + # output any variants that meet the depth coverage requirement + vcf_pos = pos + vcf_ref = ref + suffix = '' + alts = [] + safs = [] + # If we have any deletions to report, need to modify the ref string + if debug: print >> sys.stderr, "max deletions: %s" % deletions + if report_indels: + for k,v in deletions.items(): + saf = v/float(dp) + if saf >= min_allele_freq: + if len(k) > len(suffix): + suffix = k + vcf_ref = (ref + suffix).upper() + if debug: print >> sys.stderr, "snps: %s" % snps + for k,v in snps.items(): + if debug: print >> sys.stderr, "snp: %s %d" % (k,v) + saf = v/float(dp) + if saf >= min_allele_freq: + alts.append(k + suffix) + safs.append(saf) + if debug: print >> sys.stderr, "insertions: %s" % insertions + if report_indels: + for k,v in insertions.items(): + saf = v/float(dp) + if saf >= min_allele_freq: + alts.append(ref + k + suffix) + safs.append(saf) + if debug: print >> sys.stderr, "deletions: %s" % deletions + for k,v in deletions.items(): + saf = v/float(dp) + if saf >= min_allele_freq: + alts.append(vcf_ref[:len(vcf_ref) - len(k)]) # TODO alt will be a substring of vcf_ref, test this + safs.append(saf) + if len(alts) > 0: + vcf_id = "." + vcf_qual = "." + vcf_filter = "PASS" + # if not allow_multiples, report only the most freq alt + if not allow_multiples and len(alts) > 1: + max_saf = max(safs) + for i,v in enumerate(safs): + if v == max_saf: + vcf_alt = alts[i] + info = "SAF=%f;DP=%d" % (max_saf,dp) + # if allow_multiples + else: + vcf_alt = ','.join(alts) + isafs = [] + for saf in safs: + isafs.append("SAF=%f" % saf) + info = "%s;DP=%d" % (','.join(isafs),dp) + print >> outputFile,"%s\t%d\t%s\t%s\t%s\t%s\t%s\t%s" % (chrom,vcf_pos,vcf_id,vcf_ref,vcf_alt,vcf_qual,vcf_filter,info) + except Exception, e: + print >> sys.stderr, "failed: %s" % e + exit(1) + +if __name__ == "__main__": __main__() + diff -r 000000000000 -r 3890f8ba0e4d pileup_to_vcf.xml --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/pileup_to_vcf.xml Mon Feb 18 11:32:50 2013 -0500 @@ -0,0 +1,112 @@ + + Converts a pileup to VCF with filtering + pileup_to_vcf.py -i $input_file -o $output_file + #if $min_cvrg.__str__ != '': + --min_coverage $min_cvrg + #end if + #if $min_base_qual.__str__ != '': + --min_base_qual $min_base_qual + #end if + #if $min_var_pct.__str__ != '': + --min_allele_freq $min_var_pct + #end if + #if $depth_as.__str__ != 'None': + --report_depth $depth_as + #end if + $allow_multiples + $snps_only + #if $cols.select_order == 'yes' : + #if $chrom_col.__str__ != '': + --chrom_col $chrom_col + #end if + #if $pos_col.__str__ != '': + --pos_col $pos_col + #end if + #if $ref_col.__str__ != '': + --ref_col $ref_col + #end if + #if $cvrg_col.__str__ != '': + --coverage_col $cvrg_col + #end if + #if $base_call_col.__str__ != '': + --base_call_col $base_call_col + #end if + #if $base_qual_col.__str__ != '': + --base_qual_col $base_qual_col + #end if + #end if + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + Pileup to VCF converts the output of a pileup tool to a VCF representing any alleles that surpass a user specified frequency, optionally presenting multiple alleles for a given position if the allele frequency is set below 0.5. This tool assumes that any filtering for base call quality and mapping quality has been done in previous processing. + + diff -r 000000000000 -r 3890f8ba0e4d test-data/test.pileup --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/test-data/test.pileup Mon Feb 18 11:32:50 2013 -0500 @@ -0,0 +1,13 @@ +seq1 272 T 24 ,.$.....,,.,.,...,,,.,..^+. <<<+;<<<<<<<<<<<=<;<;7<& +seq1 273 T 23 ,.....,,.,.,...,,,.,..A <<<;<<<<<<<<<3<=<<<;<<+ +seq1 274 T 23 ,.$....,,.,.,...,,,.,... 7<7;<;<<<<<<<<<=<;<;<<6 +seq1 275 A 23 ,$....,,.,.,...,,,.,...^l. <+;9*<<<<<<<<<=<<:;<<<< +seq1 276 G 22 ...T,,.,.,...,,,.,.... 33;+<<7=7<<7<&<<1;<<6< +seq1 277 T 22 ....,,.,.,.C.,,,.,..G. +7<;<<<<<<<&<=<<:;<<&< +seq1 278 G 23 ....,,.,.,...,,,.,....^k. %38*<<;<7<<7<=<<<;<<<<< +seq1 279 C 23 A..T,,.,.,...,,,.,..... ;75&<<<<<<<<<=<<<9<<:<< +seq2 156 A 11 .$......+2AG.+2AG.+2AGGG <975;:<<<<< +seq3 200 A 20 ,,,,,..,.-4CACC.-4CACC....,.,,.^~. ==<<<<<<<<<<<::<;2<< +chr1 95935183 G 34 .,.,,,+1c,+1c.+1C,+1c,+1c.+1C.+1C.+1C,+1c.+1C,+1c,+1c.+1C,+1c,+1c.+1C,+1c.+1C.+1C,+1c,+1c,+1c.+1C.+1C.+1C.+1C.+1C^~c^~c IFEGIHIBIIIBAGIDI@IHCIIGHIHHEIIG!! +chr1 158571283 A 8 <,.c.c^~t^~c GIC#I#'! +chr6 125070485 C 216 <><<>>>>>>><<>>>><<<><<<<<>>>>><>>>>>><>>>>>>><><><>><><><>><>><<><<<>>>><<<>>>><<>>>><<<<<<<<<<<><<<<<<<><><<<<<><<<>><<<<<<<<>>>><<<<<<><><>>>>>>>>>>><<<<<<>><<<<>><><>>>>><>...,,,,,,,GGGGGGggggggGGGGggggggggg^~G^~g^~g^~g^~g IHHH:GFDHEBHICD@#GHHHFI9HII#I##AIIIE5@G!!!!!!!!!#!!!!!!!!$$!!$!$!#!!!