How to process list of sets having multiple element in set

When I scrape websites for all the emails on each website and try to output it, I can get a given data frame which is a list of sets of multiple elements for each website:

URL_WITH_EMAILS_DF = pd.DataFrame(data=[{'main_url': 'http://keilstruplund.dk', 'emails': [{'[email protected]', '[email protected]'}, set(),{'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]', '[email protected]', '[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]', '[email protected]', '[email protected]', '[email protected]', '[email protected]', '[email protected]', '[email protected]', '[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]', '[email protected]'}]}, 
                                    {'main_url': 'http://kirsebaergaarden.com', 'emails': [{'[email protected]'}, {'[email protected]'}, {'[email protected]'}, {'[email protected]'}, {'[email protected]'}, {'[email protected]'}, {'[email protected]'}, {'[email protected]'}, {'[email protected]'}, {'[email protected]', '[email protected]'}, {'[email protected]'}, {'[email protected]'}, {'[email protected]'}, {'[email protected]'}, {'[email protected]'}]},
                                     {'main_url': 'http://koglernes.dk', 'emails': [{'[email protected]'}, {'[email protected]'}, {'[email protected]'}, {'[email protected]'},set(), set(), {'[email protected]'}, {'[email protected]'}]},
                                      {'main_url': 'http://kongehojensbornehave.dk', 'emails': [set()]}
                                   ])

However, I want to process the data frame to look like the following:

URL_WITH_EMAILS_DF = pd.DataFrame(data=[{'main_url': 'http://keilstruplund.dk', 'emails': ['[email protected]', '[email protected]', '[email protected]', '[email protected]', '[email protected]','[email protected]', '[email protected]', '[email protected]', '[email protected]',  '[email protected]', '[email protected]', '[email protected]', '[email protected]', '[email protected]']},                                        
                                     {'main_url': 'http://kirsebaergaarden.com', 'emails': ['[email protected]']},
                                     {'main_url': 'http://koglernes.dk', 'emails': ['[email protected]']},
                                      {'main_url': 'http://kongehojensbornehave.dk', 'emails': []}
                                   ])

How can it be achieved?

I have tried the following code but it only manage to return first element of first set only while running to error when there is no element in the email list for a given website:

URL_WITH_EMAILS_DF['emails'] = [', '.join(x.pop()) if not None else "" for x in URL_WITH_EMAILS_DF['emails'].values]

PS: As per first dataframe, I needed to get a set of multiple emails to be inserted because there can be multiple webpage for a single website and I do not want to take duplicate email from each web page.