python - Combine two lists which have the same item in dict -

i have 2 lists named a_list , b_list:

a_list = [{'category_id': 1, 'category_name': u'aaa'}, \     { 'category_id': 2, 'category_name': u'bbb'}]  b_list = [{'project_count': u'20', 'category_name': u'aaa'}, \     {'project_count': u'31', 'category_name': u'bbb'}] 

i want make new list, c_list, combines a_list , b_list category_name. resulting list should like:

c_list = [{'category_id': 1,'project_count': u'20', 'category_name': u'aaa'},\     {'category_id': 2,'project_count': u'31', 'category_name': u'bbb'}] 

the goal able access both page_max , 'category_id' same 'category_name'.

for entry in c_list:     page_num =1     category_name   =  entry['category_name']     category_id     =  entry['category_id']     url = 'https://www.test.com?category_id=%(category_id)s&page=%(page)s' % {'category_id': category_id, 'page': str(page_num)}     print url      # aaa project_count 20      # bbb project_count 31     page_max = int(entry['project_count'])     in range(page_max - 1):         page_num += 1         url = 'https://www.test.com?category_id=%(category_id)s&page=%(page)s' % {'category_id': category_id, 'page': str(page_num)}         print url 

how can merge dictionaries within lists based on value of key 'category_name'?

you can create intermediate dictionary of {category_name: dict} , use update:

temp = {a['category_name']: dict(a) in a_list} b in b_list:     temp[b['category_name']].update(b) c_list = list(temp.values())    # list() unnecessary in py2.x 

but isn't guaranteed preserve order of lists. if order important:

c_list = [temp[a['category_name']] in a_list]