def cseguid(seq):
'''Returns the cSEGUID for the sequence. The cSEGUID is the url safe SEGUID checksum
calculated for the lexicographically minimal string rotation of a DNA sequence.
Only defined for circular sequences.
'''
from Bio.Seq import reverse_complement as rc
return pretty_string( seguid( min( SmallestRotation(str(seq).upper()), SmallestRotation(str(rc(seq)).upper()))))
def seguid(seq):
'''Returns the url safe SEGUID checksum for the sequence. This is the SEGUID
checksum with the '+' and '/' characters of standard Base64 encoding are respectively
replaced by '-' and '_'.
'''
return pretty_string( base64_seguid( str(seq).upper() ).replace("+","-").replace("/","_") )
