def extract_id_type(soup):
    """ Takes a BS4 object of a puchem page as input and returns the Pubchem ID type and Pubchem ID Value """
    pubhcem_uid_type = soup.find_all('meta', {'name':'pubchem_uid_type'})[0]['content']
    pubhcem_uid_value = soup.find_all('meta', {'name':'pubchem_uid_value'})[0]['content']
    return pubhcem_uid_type +':'+ pubhcem_uid_value