FASTA is a format to exchange generic information, partial or of the entire
organism.

A function "faidx" (FAsta InDeX) creates a small flat index file ".fai" allowing
for fast random access to any subsequence in the indexed FASTA file, while
loading a minimal amount of the file in to memory. This python module implements
pure Python classes for indexing, retrieval, and in-place modification of FASTA
files using a samtools compatible index. The pyfaidx module is API compatible
with the pygr seqdb module. A command-line script "faidx" is installed alongside
the pyfaidx module, and facilitates complex manipulation of FASTA files without
any programming knowledge.

WWW: https://github.com/mdshw5/pyfaidx