| 0 | 1 #!/usr/bin/env python | 
|  | 2 | 
|  | 3 """ | 
|  | 4 convert fastqsolexa file to separated sequence and quality files. | 
|  | 5 | 
|  | 6 assume each sequence and quality score are contained in one line | 
|  | 7 the order should be: | 
|  | 8 1st line: @title_of_seq | 
|  | 9 2nd line: nucleotides | 
|  | 10 3rd line: +title_of_qualityscore (might be skipped) | 
|  | 11 4th line: quality scores | 
|  | 12 (in three forms: a. digits, b. ASCII codes, the first char as the coding base, c. ASCII codes without the first char.) | 
|  | 13 | 
|  | 14 Usage: | 
|  | 15 %python fastqsolexa_to_fasta_qual.py <your_fastqsolexa_filename> <output_seq_filename> <output_score_filename> | 
|  | 16 """ | 
|  | 17 | 
|  | 18 import sys, os | 
|  | 19 from math import * | 
|  | 20 | 
|  | 21 assert sys.version_info[:2] >= ( 2, 4 ) | 
|  | 22 | 
|  | 23 def stop_err( msg ): | 
|  | 24     sys.stderr.write( "%s" % msg ) | 
|  | 25     sys.exit() | 
|  | 26 | 
|  | 27 def __main__(): | 
|  | 28     infile_name = sys.argv[1] | 
|  | 29     outfile_seq = open( sys.argv[2], 'w' ) | 
|  | 30     outfile_score = open( sys.argv[3], 'w' ) | 
|  | 31     datatype = sys.argv[4] | 
|  | 32     seq_title_startswith = '' | 
|  | 33     qual_title_startswith = '' | 
|  | 34     default_coding_value = 64 | 
|  | 35     fastq_block_lines = 0 | 
|  | 36 | 
|  | 37     for i, line in enumerate( file( infile_name ) ): | 
|  | 38         line = line.rstrip() | 
|  | 39         if not line or line.startswith( '#' ): | 
|  | 40             continue | 
|  | 41         fastq_block_lines = ( fastq_block_lines + 1 ) % 4 | 
|  | 42         line_startswith = line[0:1] | 
|  | 43         if fastq_block_lines == 1: | 
|  | 44             # first line is @title_of_seq | 
|  | 45             if not seq_title_startswith: | 
|  | 46                 seq_title_startswith = line_startswith | 
|  | 47             if line_startswith != seq_title_startswith: | 
|  | 48                 outfile_seq.close() | 
|  | 49                 outfile_score.close() | 
|  | 50                 stop_err( 'Invalid fastqsolexa format at line %d: %s.' % ( i + 1, line ) ) | 
|  | 51             read_title = line[1:] | 
|  | 52             outfile_seq.write( '>%s\n' % line[1:] ) | 
|  | 53         elif fastq_block_lines == 2: | 
|  | 54             # second line is nucleotides | 
|  | 55             read_length = len( line ) | 
|  | 56             outfile_seq.write( '%s\n' % line ) | 
|  | 57         elif fastq_block_lines == 3: | 
|  | 58             # third line is +title_of_qualityscore ( might be skipped ) | 
|  | 59             if not qual_title_startswith: | 
|  | 60                 qual_title_startswith = line_startswith | 
|  | 61             if line_startswith != qual_title_startswith: | 
|  | 62                 outfile_seq.close() | 
|  | 63                 outfile_score.close() | 
|  | 64                 stop_err( 'Invalid fastqsolexa format at line %d: %s.' % ( i + 1, line ) ) | 
|  | 65             quality_title = line[1:] | 
|  | 66             if quality_title and read_title != quality_title: | 
|  | 67                 outfile_seq.close() | 
|  | 68                 outfile_score.close() | 
|  | 69                 stop_err( 'Invalid fastqsolexa format at line %d: sequence title "%s" differes from score title "%s".' % ( i + 1, read_title, quality_title ) ) | 
|  | 70             if not quality_title: | 
|  | 71                 outfile_score.write( '>%s\n' % read_title ) | 
|  | 72             else: | 
|  | 73                 outfile_score.write( '>%s\n' % line[1:] ) | 
|  | 74         else: | 
|  | 75             # fourth line is quality scores | 
|  | 76             qual = '' | 
|  | 77             fastq_integer = True | 
|  | 78             # peek: ascii or digits? | 
|  | 79             val = line.split()[0] | 
|  | 80             try: | 
|  | 81                 check = int( val ) | 
|  | 82                 fastq_integer = True | 
|  | 83             except: | 
|  | 84                 fastq_integer = False | 
|  | 85 | 
|  | 86             if fastq_integer: | 
|  | 87                 # digits | 
|  | 88                 qual = line | 
|  | 89             else: | 
|  | 90                 # ascii | 
|  | 91                 quality_score_length = len( line ) | 
|  | 92                 if quality_score_length == read_length + 1: | 
|  | 93                     # first char is qual_score_startswith | 
|  | 94                     qual_score_startswith = ord( line[0:1] ) | 
|  | 95                     line = line[1:] | 
|  | 96                 elif quality_score_length == read_length: | 
|  | 97                     qual_score_startswith = default_coding_value | 
|  | 98                 else: | 
|  | 99                     stop_err( 'Invalid fastqsolexa format at line %d: the number of quality scores ( %d ) is not the same as bases ( %d ).' % ( i + 1, quality_score_length, read_length ) ) | 
|  | 100                 for j, char in enumerate( line ): | 
|  | 101                     score = ord( char ) - qual_score_startswith    # 64 | 
|  | 102                     qual = "%s%s " % ( qual, str( score ) ) | 
|  | 103             outfile_score.write( '%s\n' % qual ) | 
|  | 104 | 
|  | 105     outfile_seq.close() | 
|  | 106     outfile_score.close() | 
|  | 107 | 
|  | 108 if __name__ == "__main__": __main__() | 
|  | 109 |