def get_pairtree_prefix(pairtree_store):
prefix_path = os.path.join(pairtree_store, '<STR_LIT>')<EOL>with open(prefix_path, '<STR_LIT:r>') as prefixf:<EOL><INDENT>prefix = prefixf.read().strip()<EOL><DEDENT>return prefix<EOL>
Returns the prefix given in pairtree_prefix file.