[Biopython] Which Alphabet type should I use with FASTA files in Biopython?

[Sameer Farooqui]

If I'm using the FASTA files from the link below, what Alphabet type should
I use in Biopython? Would it be IUPAC.unambiguous_dna?

link to FASTA files:
http://hgdownload.cse.ucsc.edu/goldenPath/hg19/chromosomes/?C=S;O=A


- SFx