Write a program to find duplicate values ​​in Python

Topic : Find duplicate values ​​in an array or any data structure. A duplicate value is a value that occurs at least twice in an array or in a list or data structure.

Example :

 Input: ["Hoa", "Lan", "Trang", "Minh", "Hoa", "Ngoc", "Trang"] Output: ["Hoa", "Trang"]

In this article, TipsMake.com will learn with you how to write a program to determine duplicate values ​​in the Python programming language.

Write a program to find duplicate values ​​in Python

To write a program to find duplicates in Python, we need to declare a Python function that can take a list of values ​​of any data type. Here is the sample code of the program to find duplicate values ​​in Python:

def find_duplicates(x): length = len(x) duplicates = [] for i in range(length): n = i + 1 for a in range(n, length): if x[i] == x[a] and x[i] not in duplicates: duplicates.append(x[i]) return duplicates names = ["Hoa", "Lan", "Trang", "Minh", "Hoa", "Ngoc", "Trang"] print(find_duplicates(names))

The returned result is:

['Hoa', 'Trang']

The function above works like this:

1. The above function takes a list as input.
2. It then calculates the length of the list.
3. Next, it searches for the same value in the list found on the first index.
4. If it finds multiple values, it will add that value to another list containing duplicate values.
5. This process is continued until the loop reaches the last index of the list.
6. At the end of the process, it returns a list of duplicate values.

You can use this Python function for any data type.

Conclude

Finding duplicates in an array or in any data structure is one of the common interview questions. Python provides many built-in functions for finding duplicate values, but in interviewing or hiring candidate qualifications you need to use an algorithm instead of a built-in function.

TipsMake.com hopes that this article will be useful to you.

Micah Soto

Update 07 July 2023