def is_snp(reference_bases, alternate_bases):
if len(reference_bases) > <NUM_LIT:1>:<EOL><INDENT>return False<EOL><DEDENT>for alt in alternate_bases:<EOL><INDENT>if alt is None:<EOL><INDENT>return False<EOL><DEDENT>if alt not in ['<STR_LIT:A>', '<STR_LIT:C>', '<STR_LIT>', '<STR_LIT:T>', '<STR_LIT:N>', '<STR_LIT:*>']:<EOL><INDENT>return False<EOL><DEDENT><DEDENT>return True<EOL>
Return whether or not the variant is a SNP