pysam

You can fetch overlapping reads from an indexed BAM file by querying specific genomic coordinates using a unified API, applying correct coordinate conventions to ensure deterministic region-based read extraction.

Pileup-based coverage estimation is the best way to calculate depth across genomic regions in NGS pipelines, achieved by programmatically reading alignment files and computing per-base coverage directly.

To filter VCF variants, iterate through variant records to inspect INFO/FORMAT fields and sample genotypes, then write out a filtered or annotated VCF output using a unified variant file API.

Yes, you can extract reference sequences by coordinates from a FASTA file by using sequence processing abstractions to query specific genomic regions and retrieve the corresponding nucleotide context.

Coordinate conventions matter because genomic data manipulation requires deterministic file operations, and using incorrect coordinate systems during region-based read extraction or variant queries will return inaccurate alignment or sequence data.

Random access works for querying CRAM and BCF files in NGS pipelines, provided the files are properly indexed, allowing deterministic region-based extraction for both alignment and variant processing tasks.