how to find duplicate number in integer list python code example

Example 1: count the duplicates in a list in python

some_list=['a','b','c','b','d','m','n','n']

 my_list=sorted(some_list)
 
duplicates=[]
for i in my_list:
     if my_list.count(i)>1:
         if i not in duplicates:
             duplicates.append(i)
 
print(duplicates)

Example 2: program to print duplicates from a list of integers in python

lst = [ 3, 6, 9, 12, 3, 30, 15, 9, 45, 36, 12, 12]
dupItems = []
uniqItems = {}
for x in lst:
   if x not in uniqItems:
      uniqItems[x] = 1
   else:
      if uniqItems[x] == 1:
         dupItems.append(x)
      uniqItems[x] += 1
print(dupItems)