merge two dict python 3

dict.update([other])

z = {**x, **y}

def mergeDict(dict1, dict2):
   ''' Merge dictionaries and keep values of common keys in list'''
   dict3 = {**dict1, **dict2}
   for key, value in dict3.items():
       if key in dict1 and key in dict2:
               dict3[key] = [value , dict1[key]]
 
   return dict3
 
# Merge dictionaries and add values of common keys in a list
dict3 = mergeDict(dict1, dict2)
 
print('Dictionary 3 :')
print(dict3)