Version Compatibility

Reference examples tested with: BioPython 1.83+, Entrez Direct 21.0+

Before using code patterns, verify installed versions match. If versions differ:

• Python: pip show <package> then help(module.function) to check signatures

If code throws ImportError, AttributeError, or TypeError, introspect the installed package and adapt the example to match the actual API rather than retrying.

Entrez Fetch

"Download a sequence from NCBI" → Retrieve a record by accession from an NCBI database and parse it into a usable object.

• Python: Entrez.efetch() + SeqIO.read() (BioPython)
• CLI: efetch -db nucleotide -id NM_007294 -format fasta (Entrez Direct)
• R: entrez_fetch() (rentrez)

Retrieve records from NCBI databases using Biopython's Entrez module (EFetch, ESummary utilities).