PYTHON

python has duplicates

def has_duplicates(lst):
    return len(lst) != len(set(lst))
    
x = [1,2,3,4,5,5]
has_duplicates(x) 			# True

python check for duplicate

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

contains duplicate in python

#most efficient solution on Leet code
def containsDuplicate(self,nums)->bool:
        d={}
        for ele in nums:
            if ele not in d:
                d[ele] = 1
            else:
                return True
        return False