Check if All Elements in a List are Identical in Python

In Python, lists are a fundamental data structure similar to arrays in other programming languages. They can store various data types, such as strings, integers, floating point numbers, and other lists. Data is enclosed within square brackets and separated by commas within a list. Lists can be assigned to any variable name, and new values can be added using square brackets. Lists can contain duplicate values, be modified, and be sorted.

Numerous built-in functions in Python may be used to accomplish this operation. We'll examine the following methods for determining whether or not every entry in a list is equal.

1. Using all() function
2. Using set method
3. Using count() function
4. Using the Brute Force Method
5. By multiplying elements
6. Using Slicing method
7. Using itertools module

Using all() Function

The built-in all() method is used in this example. However, a little slower than other methods, this is the most elegant and straightforward method of condition checking. Because this is one of the rare instances in which Python has lazy semantics, this method even functions with an empty list. In the example provided, the all() method converts the input list into an iterable before comparing each element to see whether they are identical. If every element is the same, the output will be "Equal" if not then, "Not Equal."

Program

Output

Equal
Not Equal

Explanation

In the above code, we defined a function check(l) that checks if all the elements in list l are similar. Then, if all values are equal, it will print Equal; Otherwise, Not Equal. The code starts by initializing variable r to False. Next, it checks that the list length is less than 0 and then sets r to True. Here, we used a generator expression with the all() function to check all the elements in the provided list are the same as the first element.

Using set() Method

Copying objects is prohibited in collections. Additionally, each item in your classification must be able to be hashed. Utilizing this characteristic, we can ascertain if all elements in a list are identical. As seen below, the list is transformed into a set in this example by supplying the list name to the set() function. The set will check every element in the original list, and if they are all identical, the set will only contain one unique element. If the entries in your list are different, the software will return Not Equal, or else it will return Equal.

Program

Output

Equal
Not Equal

Explanation

In the above code section, we define a function test(l) that checks if all elements in the list l are similar. It does this by converting the list to a set and then checking if the length of the set is 1. Then, it checks if all elements in the list are the same.

Using count() Function

Because the count() function only counts the first element, and the set() technique operates on sequences rather than iterables, this method is quicker than using set(). To obtain the right count, this approach must thoroughly verify each element. This function assumes that the list is not empty. Two functions, count and len, are utilized in this example and are both simple to construct. The list length using len() will thus match the number of times the element appears in the list using count() if the same element appears repeatedly.

Program

Output

Equal
Not Equal

Explanation

The above code defines a function test that checks if all elements in a list are equal. The logic is that the occurrences of the first element are counted and compared to the whole list length. In the above example, we created two lists: the first with the same values and the second with different values.

Check All Elements using the Brute Force Method

Using the Brute Force Approach, we can iterate through the list and compare each element with the first. If all elements match, the list contains identical elements. Otherwise, it doesn't. Here is an example using this method:

Example

Output

False
True

Explanation

The above code defines a function named chk_similar_values that checks if all elements in a list are the same. It returns True if all elements are the same and False otherwise. my_list1 contains different elements in the lists so that it will return False. While my_list2 contains similar elements [5, 5, 5], it will return True.

Check all Elements by Multiplying the Elements

Another way to ensure that all elements in a Python list are similar is to multiply the starting element by the total number of elements in the list and then compare it to the original list.

Example

Output

False
True

Explanation

In the above program, we created a function named chk_similar_values that checks all similar elements in the given list. Then, we create a new list inserted with only the first element and then compare this to the original list. If all elements are similar, the function will return True. Otherwise, it will return False.

Check all Elements using the Slicing Method

This method analyzes the original list from the second to the last element and compares it with the newly created list from the first to the second-to-last element. If both lists are similar, then all elements will be matched. It will give the output True; if lists are not similar, give the output False.

Example

Output

True
False

Explanation

The above code defines a function named `chk_similar_values` that checks if all elements in a list are the same. It compares the list sliced from the second element to the end with the list sliced from the beginning to the second-to-last element. If they are equal, it returns True, indicating that all elements in the list are the same.

Check all Elements using the itertools

We can use the groupby function from the itertools module in this method. It groups consecutive identical elements. If there's only one group (i.e., all elements are identical), the list contains identical elements.

Program

Output

False
True

Explanation

The code defines a function named all_equal that checks if all elements in an iterable are the same. It uses the groupby function from the itertools module to group consecutive identical elements. If there's only one group, all elements are identical, and it returns True; otherwise, it returns False.

Conclusion

In Python, several ways exist to check if all elements in a list are identical. You can go with the abovementioned methods, such as brute force, count method, etc. Ensuring all elements match is essential for various programming tasks regardless of the approach.