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Commit ee9aabdf authored by Monika Komorowska's avatar Monika Komorowska
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support for empty lines and fasta sequence section

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modules/Bio/EnsEMBL/Utils/IO/GFFParser.pm
+ 179
− 104
View file @ ee9aabdf
=pod
=head1 LICENSE
......@@ -24,7 +23,6 @@ Monika Komorowska, 2012 - monika@ebi.ac.uk
use strict;
use Bio::EnsEMBL::Utils::IO::GFFParser;
use Bio::EnsEMBL::Utils::Scalar qw/wrap_array/;
use FileHandle;
my $file_name = "features.gff";
......@@ -47,21 +45,34 @@ while (defined($feature) ) {
#do something with the feature, e.g. print hash keys and values
foreach my $key (keys %feature) {
if ($key ne 'attribute') {
print $key . " " . $feature{$key} ."\n";
} else {
print $key . "\n";
my %attribs = %{$feature{$key}};
foreach my $attrib_key (keys %attribs) {
my $values = $attribs{$attrib_key};
printf("\t%s %s\n", $attrib_key, join(q{, }, @{wrap_array($values)}));
}
}
if ($key ne 'attribute') {
print $key . " " . $feature{$key} ."\n";
} else {
print $key . "\n";
my %attribs = %{$feature{$key}};
foreach my $attrib_key (keys %attribs) {
printf("\t%s %s\n", $attrib_key, join(q{, }, @{wrap_array($values)}));
}
}
}
print "\n\n";
$feature = $parser->parse_next_feature();
}
my $sequence = $parser->parse_next_sequence();
while (defined($sequence)) {
my %sequence = %{$sequence};
foreach my $key (keys %sequence) {
print $key . " " . $sequence{$key} ."\n";
}
print "\n\n";
$sequence = $parser->parse_next_sequence();
}
$parser->close();
$fh->close();
......@@ -70,7 +81,7 @@ $fh->close();
=head1 DESCRIPTION
GFF3 format as defined in http://www.sequenceontology.org/gff3.shtml.
GFF3 format as defined in http://www.sequenceontology.org/gff3.shtml
Use parse_header method to parse a GFF3 file header, and parse_next_feature to parse the next feature line in the file.
......@@ -85,8 +96,10 @@ use warnings;
use Bio::EnsEMBL::Utils::Exception;
use IO::File;
use URI::Escape;
use Bio::EnsEMBL::Utils::Scalar qw/wrap_array/;
my %strand_conversion = ( '+' => '1', '?' => '0', '-' => '-1' );
my %strand_conversion = ( '+' => '1', '?' => '0', '-' => '-1');
=head2 new
......@@ -98,13 +111,15 @@ my %strand_conversion = ( '+' => '1', '?' => '0', '-' => '-1' );
=cut
sub new {
my $class = shift;
my $self = { filehandle => shift, };
bless $self, $class;
if ( !defined( $self->{'filehandle'} ) ) {
throw("GFFParser requires a valid filehandle to a GFF3 formatted file");
}
return $self;
my $class = shift;
my $self = {
filehandle => shift,
};
bless $self, $class;
if (!defined($self->{'filehandle'})) {
throw("GFFParser requires a valid filehandle to a GFF3 formatted file");
}
return $self;
}
......@@ -118,31 +133,31 @@ sub new {
sub parse_header {
my $self = shift;
my $self = shift;
my $next_line;
my @header_lines;
while ( ( $next_line = $self->_read_line() ) && ( $next_line =~ /^[\#|\s]/ ) )
{
#header lines start with ##
if ( $next_line =~ /^[\#]{2}/ ) {
push @header_lines, $next_line;
if ( $next_line =~ /gff-version\s+(\d+)/ ) {
if ( $1 != 3 ) {
warning(
"File has been formatted in GFF version $1. GFFParser may return unexpected results as it is designed to parse GFF3 formatted files."
);
}
}
my $next_line;
my @header_lines;
while (($next_line = $self->_read_line()) && ($next_line =~ /^[\#|\s]/) ) {
#stop parsing features if ##FASTA directive encountered
last if ($next_line =~ /\#\#FASTA/ );
#header lines start with ## (except for the ##FASTA directive indicating sequence section)
if ($next_line =~ /^[\#]{2}/ ) {
push @header_lines, $next_line;
if ($next_line =~ /gff-version\s+(\d+)/) {
if ($1 != 3) {
warning("File has been formatted in GFF version $1. GFFParser may return unexpected results as it is designed to parse GFF3 formatted files.");
}
}
}
}
}
if ( defined($next_line) && ( $next_line !~ /^[\#|\s]/ ) ) {
$self->{'first_feature_line'} = $next_line;
}
return \@header_lines;
if (defined($next_line)) {
$self->{'first_non_header_line'} = $next_line;
}
return \@header_lines;
}
......@@ -162,93 +177,153 @@ sub parse_header {
attribute => hashref,
}
If the attribute value held more than one value then we hold an arrayref
not a scalar
Returntype : Hashref of a GFF3 feature line
=cut
sub parse_next_feature {
my $self = shift;
my $self = shift;
# my $next_line;
my $feature_line;
while ( my ($next_line) = $self->_read_line() ) {
next
if ( $next_line =~ /^\#/
|| $next_line =~ /^\s*$/
|| $next_line =~ /^\/\// );
$feature_line = $next_line;
last;
}
return undef unless $feature_line;
my $next_line;
my $feature_line;
while (($next_line = $self->_read_line() ) && defined($next_line) ) {
my %feature;
my %attribute;
#stop parsing features if ##FASTA directive
last if ($next_line =~ /\#\#FASTA/);
#strip off trailing comments
$feature_line =~ s/\#.*//;
my @chunks = split( /\t/, $feature_line );
next if ($next_line =~ /^\#/ || $next_line =~ /^\s*$/ ||
$next_line =~ /^\/\//);
%feature = (
'seqid' => uri_unescape( $chunks[0] ),
'source' => uri_unescape( $chunks[1] ),
'type' => uri_unescape( $chunks[2] ),
'start' => $chunks[3],
'end' => $chunks[4],
'score' => $chunks[5],
'strand' => $strand_conversion{ $chunks[6] },
'phase' => $chunks[7]
);
$feature_line = $next_line;
last;
}
if ( $chunks[8] ) {
return undef unless $feature_line;
my %feature;
my %attribute;
#strip off trailing comments
$feature_line =~ s/\#.*//;
my @chunks = split(/\t/, $feature_line);
%feature = (
'seqid' => uri_unescape($chunks[0]),
'source' => uri_unescape($chunks[1]),
'type' => uri_unescape($chunks[2]),
'start' => $chunks[3],
'end' => $chunks[4],
'score' => $chunks[5],
'strand' => $strand_conversion{$chunks[6]},
'phase' => $chunks[7]
);
if ($chunks[8]) {
my @attributes = split( /;/, $chunks[8] );
my %attributes;
foreach my $attribute (@attributes) {
my ( $name, $value ) = split( /=/, $attribute );
$name = uri_unescape($name);
my @split_values = map { uri_unescape($_) } split(/,/, $value);
if(scalar(@split_values) > 1) {
$attributes{$name} = \@split_values;
}
else {
$attributes{$name} = $split_values[0];
my %attributes;
foreach my $attribute (@attributes) {
my ( $name, $value ) = split( /=/, $attribute );
$name = uri_unescape($name);
my @split_values = map { uri_unescape($_) } split(/,/, $value);
if(scalar(@split_values) > 1) {
$attributes{$name} = \@split_values;
}
else {
$attributes{$name} = $split_values[0];
}
}
$feature{'attribute'} = \%attributes;
}
$feature{'attribute'} = \%attributes;
}
return \%feature;
return \%feature;
}
sub _read_line {
=head2 parse_next_sequence
my $self = shift;
my $fh = $self->{'filehandle'};
Arg [1] : File handle
Description: Returns a hashref in the format -
{
header => scalar,
sequence => scalar,
}
Returntype : Hashref of a GFF3 sequence line
my $line;
=cut
sub parse_next_sequence {
my $self = shift;
if ( defined( $self->{'first_feature_line'} ) ) {
$line = $self->{'first_feature_line'};
$self->{'first_feature_line'} = undef;
}
else {
$line = <$fh>;
if ( defined($line) ) {
chomp $line;
my $next_line;
my $sequence;
my $header;
while (($next_line = $self->_read_line() ) && defined($next_line) ) {
next if ($next_line =~ /^\#/ || $next_line =~ /^\s*$/ ||
$next_line =~ /^\/\//);
if ($next_line =~ /^>/) {
if ($header) {
#next fasta header encountered
$self->{'next_fasta_header'} = $next_line;
last;
} else {
$header = $next_line;
}
} else {
$sequence .= $next_line;
}
}
}
return $line;
return undef unless ($sequence || $header);
my %sequence = (header => $header , sequence => $sequence );
return \%sequence;
}
sub _read_line {
my $self = shift;
my $fh = $self->{'filehandle'};
my $line;
if (defined($self->{'first_non_header_line'})) {
$line = $self->{'first_non_header_line'};
$self->{'first_non_header_line'} = undef;
} elsif ( defined($self->{'next_fasta_header'} )) {
$line = $self->{'next_fasta_header'};
$self->{'next_fasta_header'} = undef;
}
else {
$line = <$fh>;
if (defined($line)) {
chomp $line;
if (!$line) {
#parse next line if current line is empty
$line = $self->_read_line();
}
}
}
return $line;
}
sub close {
my $self = shift;
$self->{"filehandle"} = undef;
my $self = shift;
$self->{"filehandle"} = undef;
}
1;
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