Off topic:protein coding gene from a gff3 file

Question

[rajesh]

i have a GFF3 file of human chromosome. it contain CDS, exon, transcript , gene in its 3rd column, but i want to extract only protein coding genes from this file, which one contain this information. i am attaching the file

 Y  havana  five_prime_UTR  6246223 6246268 .   +   .   Parent=transcript:ENST00000429039
    Y   havana  exon    6246223 6246355 .   +   .   Parent=transcript:ENST00000429039;Name=ENSE00003749301;constitutive=0;ensembl_end_phase=0;ensembl_phase=-1;exon_id=ENSE00003749301;rank=1;version=1
    Y   havana  CDS 6246269 6246355 .   +   0   ID=CDS:ENSP00000414049;Parent=transcript:ENST00000429039;protein_id=ENSP00000414049
    Y   havana  exon    6246617 6246754 .   +   .   Parent=transcript:ENST00000429039;Name=ENSE00001608967;constitutive=0;ensembl_end_phase=0;ensembl_phase=0;exon_id=ENSE00001608967;rank=2;version=1
    Y   havana  CDS 6246617 6246754 .   +   0   ID=CDS:ENSP00000414049;Parent=transcript:ENST00000429039;protein_id=ENSP00000414049
    Y   havana  exon    6247356 6247433 .   +   .   Parent=transcript:ENST00000429039;Name=ENSE00003546295;constitutive=0;ensembl_end_phase=0;ensembl_phase=0;exon_id=ENSE00003546295;rank=3;version=1
    Y   havana  CDS 6247356 6247433 .   +   0   ID=CDS:ENSP00000414049;Parent=transcript:ENST00000429039;protein_id=ENSP00000414049
    Y   havana  exon    6247562 6247673 .   +   .   Parent=transcript:ENST00000429039;Name=ENSE00001623435;constitutive=0;ensembl_end_phase=1;ensembl_phase=0;exon_id=ENSE00001623435;rank=4;version=1
    Y   havana  CDS 6247562 6247673 .   +   0   ID=CDS:ENSP00000414049;Parent=transcript:ENST00000429039;protein_id=ENSP00000414049
    Y   havana  exon    6247775 6247920 .   +   .   Parent=transcript:ENST00000429039;Name=ENSE00001642228;