Answers for "how to check for duplicates in a list"

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)

python check for duplicate

def checkDuplicate(user):
    if len(set(user)) < len(user):
        return True
    return False