check for duplicates in 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: python count repeated elements in a list

# Basic syntax:
dict_of_counts = {item:your_list.count(item) for item in your_list}

# Example usage:
your_list = ["a", "b", "a", "c", "c", "a", "c"]
dict_of_counts = {item:your_list.count(item) for item in your_list}
print(dict_of_counts)
--> {'a': 3, 'b': 1, 'c': 3}

Example 3: python has duplicates

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

Example 4: duplicate in list 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])

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Example 5: how to check if there are duplicates in a list python

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

Example 6: python check for duplicate

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