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

how to check if there are duplicates in a list python

>>> your_list = ['one', 'two', 'one']
>>> len(your_list) != len(set(your_list))
True

check list for duplicate values python

a = [1,2,3,2,1,5,6,5,5,5]

import collections
print([item for item, count in collections.Counter(a).items() if count > 1])

## [1, 2, 5]