--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/blastn_to_scaffold.py	Sun Jun 21 14:41:10 2015 -0400
@@ -0,0 +1,120 @@
+#!/usr/bin/python
+import sys
+import argparse
+
+def insert_newlines(string, every=60):
+    lines = []
+    for i in xrange(0, len(string), every):
+        lines.append(string[i:i+every])
+    return '\n'.join(lines)
+    
+def getseq (fastadict, transcript, up, down, orientation="direct"):
+    def reverse (seq):
+        revdict = {"A":"T","T":"A","G":"C","C":"G","N":"N"}
+        revseq = [revdict[i] for i in seq[::-1]]
+        return "".join(revseq)
+    pickseq = fastadict[transcript][up-1:down]
+    if orientation == "direct":
+        return pickseq
+    else:
+        return reverse(pickseq)
+
+def Parser():
+    the_parser = argparse.ArgumentParser(
+        description="Generate DNA scaffold from blastn alignment of Contigs")
+    the_parser.add_argument(
+        '--sequences', action="store", type=str, help="input sequence file in fasta format")
+    the_parser.add_argument(
+        '--guideSequence', action="store", type=str, help="the reference sequence to guide the scaffold assembly in fasta format")
+    the_parser.add_argument(
+        '--blastn-tab', dest="blastn_tab", action="store", type=str, help="13-columns tabular blastn output")
+    the_parser.add_argument(
+        '--output', action="store", type=str, help="output file path, fasta format")
+    args = the_parser.parse_args()
+    return args
+    
+def blatnInfo (file):
+    blastlist = []
+    with open(file, "r") as f:
+        for line in f:
+            minilist = []
+            fields = line.rstrip().split()
+            minilist.append(fields[0])
+            minilist.extend(fields[6:10])
+            blastlist.append(minilist)
+    blastlist.sort(key=lambda x: x[3], reverse=True)
+    return blastlist
+    
+def myContigs (file):
+    Contigs = {}
+    with open(file, "r") as f:
+        for line in f:
+            if line[0] == ">":
+                header = line[1:-1]
+                Contigs[header] = ""
+            else:
+                Contigs[header] += line[:-1]
+    return Contigs
+    
+def myGuide (file):
+    Guide = {}
+    coordinate = 0
+    with open(file, "r") as f:
+        for line in f:
+            if line[0] == ">":
+                continue
+            else:
+                for nucleotide in line[:-1]:
+                    coordinate += 1
+                    Guide[coordinate] = nucleotide.lower()
+    return Guide
+
+def updateGuide (blastlist, GuideDict, ContigsDict):
+    '''
+    the blastlist object is a list of list with
+    element [0] : name of the blasted Contig
+    element [1] : queryStart of the alignment to the reference
+    element [2] = queryStop of the alignment to the reference        
+    element [3] : subjectStart of the alignment to the reference
+    element [4] = subjectStop of the alignment to the reference        
+    '''
+    for fields in blastlist:
+        seqHeader = fields[0]
+        queryStart = int(fields[1])
+        queryStop = int(fields[2])
+        subjectStart = int(fields[3])
+        subjectStop = int(fields[4])
+        if subjectStart > subjectStop:
+            subjectStart, subjectStop = subjectStop, subjectStart
+            orientation = "reverse"
+        else:
+            orientation = "direct"
+        sequence = getseq (ContigsDict, seqHeader, queryStart, queryStop, orientation)
+        for i in range(subjectStart, subjectStop+1):
+            try:
+                del GuideDict[i]
+            except KeyError:
+                continue
+        for i, nucleotide in enumerate(sequence):
+            GuideDict[i+subjectStart] = nucleotide
+            
+def finalAssembly (GuideDict, outputfile):
+    finalSeqList = []
+    for keys in sorted(GuideDict):
+        finalSeqList.append(GuideDict[keys])
+    finalSequence = insert_newlines("".join(finalSeqList) )
+    Out = open (outputfile, "w")
+    print >> Out, ">Scaffold"
+    print >> Out, finalSequence
+    Out.close()
+    
+def __main__():
+    args = Parser()
+    ContigsDict = myContigs (args.sequences)
+    GuideDict = myGuide (args.guideSequence)
+    blastlist = blatnInfo(args.blastn_tab)
+    updateGuide(blastlist, GuideDict, ContigsDict)
+    finalAssembly(GuideDict, args.output)
+
+if __name__ == "__main__":
+    __main__()