Mercurial > repos > yufei-luo > s_mart
diff commons/core/parsing/FastaParser.py @ 6:769e306b7933
Change the repository level.
author | yufei-luo |
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date | Fri, 18 Jan 2013 04:54:14 -0500 |
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children | 94ab73e8a190 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/commons/core/parsing/FastaParser.py Fri Jan 18 04:54:14 2013 -0500 @@ -0,0 +1,173 @@ +# +# Copyright INRA-URGI 2009-2010 +# +# This software is governed by the CeCILL license under French law and +# abiding by the rules of distribution of free software. You can use, +# modify and/ or redistribute the software under the terms of the CeCILL +# license as circulated by CEA, CNRS and INRIA at the following URL +# "http://www.cecill.info". +# +# As a counterpart to the access to the source code and rights to copy, +# modify and redistribute granted by the license, users are provided only +# with a limited warranty and the software's author, the holder of the +# economic rights, and the successive licensors have only limited +# liability. +# +# In this respect, the user's attention is drawn to the risks associated +# with loading, using, modifying and/or developing or reproducing the +# software by the user in light of its specific status of free software, +# that may mean that it is complicated to manipulate, and that also +# therefore means that it is reserved for developers and experienced +# professionals having in-depth computer knowledge. Users are therefore +# encouraged to load and test the software's suitability as regards their +# requirements in conditions enabling the security of their systems and/or +# data to be ensured and, more generally, to use and operate it in the +# same conditions as regards security. +# +# The fact that you are presently reading this means that you have had +# knowledge of the CeCILL license and that you accept its terms. +# +import sys +from commons.core.parsing.SequenceListParser import SequenceListParser +from SMART.Java.Python.structure.Sequence import Sequence +from SMART.Java.Python.misc.UnlimitedProgress import UnlimitedProgress + +class FastaParser(SequenceListParser): + """A class that reads a list of sequences in FASTA""" + + def __init__(self, fileName, verbosity = 0): + super(FastaParser, self).__init__(fileName, verbosity) + self.tags = {} + + + def getTags(self): + return self.tags + + + def getFileFormats(): + return ["fasta", "mfa", "fas"] + getFileFormats = staticmethod(getFileFormats) + + + def getInfos(self): + """ + Get some generic information about the sequences + """ + self.nbSequences = 0 + self.size = 0 + self.reset() + progress = UnlimitedProgress(100000, "Reading input file", self.verbosity - 9) + for line in self.handle: + line = line.strip() + if line == "": + continue + if line[0] == ">": + self.nbSequences += 1 + else: + self.size += len(line) + progress.inc() + progress.done() + self.reset() + + + def parseOne(self): + """ + Parse only one element in the file + """ + name = None + string = "" + + if self.currentLine != None: + if self.currentLine[0] != ">": + raise Exception("First line is weird: %s" % (self.currentLine)) + name = self.currentLine[1:].split()[0] + self.currentLine = None + + for line in self.handle: + line = line.strip() + if line == "": + pass + elif line[0] == ">": + if name == None: + name = line[1:].split()[0] + else: + self.currentLine = line + return Sequence(name, string) + else: + string += line + + if name == None: + return None + return Sequence(name, string) + + + def setTags(self): + mark = self.handle.tell() + thisTag = mark + + line = self.handle.readline() + while line != "": + if line[0] == ">": + line = line.strip() + self.tags[line[1:].split()[0]] = thisTag + thisTag = self.handle.tell() + line = self.handle.readline() + + self.handle.seek(mark) + + + def getSubSequence(self, chromosome, start, end, direction, name = None): + if not self.tags: + self.setTags() + + if chromosome not in self.tags: + raise Exception("Cannot find " + chromosome) + + if name == None: + name = "%s:%d-%d (%d)" % (chromosome, start, end, direction) + sequence = Sequence(name) + + # switch from 0-based to 1-based coordinates + start -= 1 + end -= 1 + + self.handle.seek(self.tags[chromosome]) + line = self.handle.readline().strip() + if line != ">" + chromosome: + raise Exception("Arrived in a wrong place (got %s)" % (line)) + + position1 = self.handle.tell() + line = self.handle.readline().strip() + position2 = self.handle.tell() + size = len(line) + address = position1 + ((start - (start % size)) / size) * (position2 - position1); + + count = max(0, start - (start % size)); + self.handle.seek(address) + + newSequence = "" + for line in self.handle: + line = line.strip() + + if line[0] == ">": + break + + subStart = start - count + if subStart < 0: + subStart = 0 + subEnd = end - count + subSize = subEnd - subStart + 1 + if subSize + subStart > len(line): + subSize = len(line) - subStart + if subEnd < 0: + break + if subStart <= len(line): + newSequence += line[subStart:subStart+subSize] + count += len(line) + + if newSequence == "": + raise Exception("Error, sequence %s is empty" % (name)) + sequence.sequence = newSequence + if direction == -1: + sequence.reverseComplement() + return sequence