Попробуйте преобразовать его в dict:
data= "[['Categories', [['180972'], ['180800'], ['16228'], ['32733'], ['32789'], ['32833'], ['325137'], ['32839'], ['25329'], ['42605'], ['428240849'], ['5101'], ['568'], ['570716'], ['57116'], ['57080545404'], ['57083134076']]], ['Tags', ['Stock', 'Color', 'Fam', 'Dress','Maxi']], ['Type', ['Luxary']], ['Vendor', ['AAA']]]"
data = eval(data)
d={}
for i in data:
d[i[0]] = [x for x, in i[1]] if isinstance(i[1][0], list) else i[1]
Вывод будет:
{'Categories':
['180972',
'180800',
'16228',
'32733',
'32789',
'32833',
'325137',
'32839',
'25329',
'42605',
'428240849',
'5101',
'568',
'570716',
'57116',
'57080545404',
'57083134076'],
'Tags': ['Stock', 'Color', 'Fam', 'Dress', 'Maxi'],
'Type': ['Luxary'],
'Vendor': ['AAA']
}