Python slice last element

Python Get the last element of a list

Have you ever needed to get the last element of a list in Python, but weren’t sure of the best way to do it? There are several different methods you can use. In this article, we will discuss these methods in detail and provide code examples for each.

Just to be real quick, we can get the last element of a Python list by negative indexing, the pop() method, list slicing, and list comprehension. We will give examples of each method.

1. Quick Examples of Getting Last Element of List

These quick examples give a high-level overview of the methods that can be used to get the last element of a list. These examples will give a quick introduction to each method we will discuss each detail later on.

2. Get Last Element of the List using Indexing

In Python, you can get the last element by using -1 as the index value of the list. This is the most common method for getting the last element of a list in Python.

Lists in Python are zero-indexed, which means that the first element has an index of 0, the second element has an index of 1, and so on. To get the last element of a list using indexing, you should use index -1. This index refers to the last element of the list.

3. Get Last 2 Elements of the List

One of the simplest ways to get the last two elements of a list is to use negative indexing with a list slice. we use negative indexing to access the second-to-last element of the list with the index -2, and then slice the list from that index to the end of the list using the slice notation -2: .

See the following example:

4. Using pop() to Get Last Element

The pop() method is a commonly used method in Python lists that removes and returns the last element of a list. We can use this method to get the last element of a list.

The pop() method modifies the original list, so we should only use this method when it is okay to update the original list.

5. List Slicing Get Last Element as a List

If we want to extract only the last element of a list using slicing, we can specify an index of -1 as the starting index and leave the end index unspecified.

We use the [-1:] syntax to extract a subset of the list starting from the last element and going all the way to the end of the list. This syntax returns a new list with only one element, which is the last element of the original list.

List slicing can be less efficient than using indexing or the pop() method, especially when dealing with large lists. This is because list slicing creates a new list, which can take up additional memory and processing time.

6. Using List comprehension

To get the last element of a list using list comprehension, we can create a new list containing only the last element of the original list.

We use list comprehension to create a new list containing only the last element of the original list. it allows us to perform additional transformations or filters on the data, if needed.

7. Fastest Method – indexing, pop(), and list slicing

In the above sections, we have discussed all these three methods. Let’s draw a run time comparison between these methods. On my machine the pop() and indexing methods almost took the same time. while the list slicing method took twice.

Yields the following output. Here I use timeit to measure the time of each method.

8. Summary and Conclusion

We have covered multiple ways to get the last element of a list in Python. Among them we learned a simple indexing approach, using the pop() method, list slicing, and list comprehension. If you have any queries please feel free to leave a comment below.

You may also like reading:

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I am a software Engineer with extensive 4+ years of experience in Programming related content Creation.

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Get the last element of a list in Python

Lists are one of the most commonly used data structures in python programs. In this article, we will look at different ways to get the last element of a list in python. For this, we will use ways like indexing, pop() method, slicing and reverse iterator.

Get the last element of a list using indexing in Python

Indexing in python is a way to access elements from a list. In python, we can use positive indices as well as negative indices. Positive indices start with zero which corresponds to the first element of the list and the last element of the list is identified by the index “listLen-1” where “listLen” is the length of the list.

Alternatively, negative indices start from -1 which corresponds to the last element of the list. It goes till “-listLen” where listLen is the length of the list. The index “-listLen” corresponds to the first element in the list.

To get the last element of a list, we can first find the length of the list using the len() function. Then we can access the last element of the list at the index “listLen-1” as follows.

myList = [1, 2, 3, 4, 5, 6, 7] print("Given List is:", myList) listLen = len(myList) lastElement = myList[listLen - 1] print("Last element of the list is:", lastElement)

Given List is: [1, 2, 3, 4, 5, 6, 7] Last element of the list is: 7

Alternatively, we can use negative indexing to access the last element of the list. The last element of the list is at index -1 which can be accessed as follows.

myList = [1, 2, 3, 4, 5, 6, 7] print("Given List is:", myList) lastElement = myList[- 1] print("Last element of the list is:", lastElement)

Given List is: [1, 2, 3, 4, 5, 6, 7] Last element of the list is: 7

We can see that while using negative indexing, we don’t have to calculate the length of the list.

Using the pop() method

The pop() method is used to remove any element from the list from a specified index. It takes the index of the element as an optional input parameter and returns the element at the specified index after deleting it from the list. If no input parameter is passed, it will return the last element of the list after deleting it.

We can use the pop() method to get the last element of the list as follows.

myList = [1, 2, 3, 4, 5, 6, 7] print("Given List is:", myList) lastElement = myList.pop() print("Last element of the list is:", lastElement)

Given List is: [1, 2, 3, 4, 5, 6, 7] Last element of the list is: 7

Remember that the pop() method also deletes the element which is accessed. So, Use this method only when you also want to delete the last element of the list.

Get the last element of a list using Slicing in Python

In python, slicing is an operation to create a subpart of a string or a list. With slicing, we can access different parts of any string, tuple or a list. To perform slicing on a list named, we use the syntax listName[start, end,interval] where “start” and “end” are the indices at which the sliced list starts and ends in the original list respectively. The “interval” is used to select elements in a sequence. The elements are selected from the list at the indices which are whole number multiples of “interval” away from the start index.

To access the last element of a list using slicing in python, we can slice a list in such a way that it contains only the last element. Then we can access that element as follows.

myList = [1, 2, 3, 4, 5, 6, 7] print("Given List is:", myList) lastElement = myList[-1:][0] print("Last element of the list is:", lastElement)

Given List is: [1, 2, 3, 4, 5, 6, 7] Last element of the list is: 7

Get the last element of a list using reverse iterator

We can use a reverse iterator to get the last element of the list. To create a reverse iterator, we can use the reversed() method. The reversed() method takes any iterable object as input and returns a reverse iterator of the iterable.

To get the last element of a list, we will first create a reverse iterator of the list using the reversed() method. Then we will access the first element of the reverse iterator which will be the last element of the original list. This can be done as follows.

myList = [1, 2, 3, 4, 5, 6, 7] print("Given List is:", myList) reverseIter = reversed(myList) lastElement = next(reverseIter) print("Last element of the list is:", lastElement) 

Given List is: [1, 2, 3, 4, 5, 6, 7] Last element of the list is: 7

Get the last element of a list using itemgetter

We can create an itemgetter object to access the last element of a list. The itemgetter() method is defined in the operator module in python. The itemgetter() method takes the index as input which creates a callable object. The callable object takes an iterable as input and extracts the element at the specified index.

To access the last element of the list, we can call itemgetter() method with input index as -1 and then we can access the last element of the list as follows.

import operator myList = [1, 2, 3, 4, 5, 6, 7] print("Given List is:", myList) lastElement = operator.itemgetter(-1)(myList) print("Last element of the list is:", lastElement)

Given List is: [1, 2, 3, 4, 5, 6, 7] Last element of the list is: 7

Conclusion

In this article, we have seen different ways to get the last element of a list in python. To read more about lists, read this article on list comprehension in python. Stay tuned for more informative articles.

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Python Get the last element of a list

Have you ever needed to get the last element of a list in Python, but weren’t sure of the best way to do it? There are several different methods you can use. In this article, we will discuss these methods in detail and provide code examples for each.

Just to be real quick, we can get the last element of a Python list by negative indexing, the pop() method, list slicing, and list comprehension. We will give examples of each method.

1. Quick Examples of Getting Last Element of List

These quick examples give a high-level overview of the methods that can be used to get the last element of a list. These examples will give a quick introduction to each method we will discuss each detail later on.

2. Get Last Element of the List using Indexing

In Python, you can get the last element by using -1 as the index value of the list. This is the most common method for getting the last element of a list in Python.

Lists in Python are zero-indexed, which means that the first element has an index of 0, the second element has an index of 1, and so on. To get the last element of a list using indexing, you should use index -1. This index refers to the last element of the list.

3. Get Last 2 Elements of the List

One of the simplest ways to get the last two elements of a list is to use negative indexing with a list slice. we use negative indexing to access the second-to-last element of the list with the index -2, and then slice the list from that index to the end of the list using the slice notation -2: .

See the following example:

4. Using pop() to Get Last Element

The pop() method is a commonly used method in Python lists that removes and returns the last element of a list. We can use this method to get the last element of a list.

The pop() method modifies the original list, so we should only use this method when it is okay to update the original list.

5. List Slicing Get Last Element as a List

If we want to extract only the last element of a list using slicing, we can specify an index of -1 as the starting index and leave the end index unspecified.

We use the [-1:] syntax to extract a subset of the list starting from the last element and going all the way to the end of the list. This syntax returns a new list with only one element, which is the last element of the original list.

List slicing can be less efficient than using indexing or the pop() method, especially when dealing with large lists. This is because list slicing creates a new list, which can take up additional memory and processing time.

6. Using List comprehension

To get the last element of a list using list comprehension, we can create a new list containing only the last element of the original list.

We use list comprehension to create a new list containing only the last element of the original list. it allows us to perform additional transformations or filters on the data, if needed.

7. Fastest Method – indexing, pop(), and list slicing

In the above sections, we have discussed all these three methods. Let’s draw a run time comparison between these methods. On my machine the pop() and indexing methods almost took the same time. while the list slicing method took twice.

Yields the following output. Here I use timeit to measure the time of each method.

8. Summary and Conclusion

We have covered multiple ways to get the last element of a list in Python. Among them we learned a simple indexing approach, using the pop() method, list slicing, and list comprehension. If you have any queries please feel free to leave a comment below.

You may also like reading:

AlixaProDev

I am a software Engineer with extensive 4+ years of experience in Programming related content Creation.

Источник