Lists homework help
Lists in python are one of the data types that you will be using more often. What differentiates lists from the other data types is their versatility. Here is a snippet of what you will learn in this article about lists:-
What are lists
Methods of list creation.
Features of a list.
How to manipulate
List methods
What are lists and methods of list creation?
List in python is akin to the shopping list that you make before going to a supermarket. They both are an ordered collection of things. In python, a list is created using the method list(). Alternatively, we can create the list by writing the ordered items inside the parentheses []. The individual elements of the list have to be separated by a comma.
If you want to impress your friends with some exquisite knowledge in sophisticated list creation methods such as using 'lambda expressions' and 'for loops' to create a list. Then please refer to the content below: -
Here are the key features of a list.
1. A list is an ordered collection of items.
The key statement in defining a list is that it's an ordered collection of items. The weight on the ordered collection is much heavier. Two lists can have the same number and identical elements, but a distinguishing feature of the two elements can be the order of the items.
2. All kinds of elements.
Lists can contain other data types all in it. Like the list could have the first element as an integer and the third element as a float or a string. On the same note, the first integer could be duplicated in the list. Additionally, a list can contain any number of items depending on what your memory can manage. Note, the first element is indexed as zero.
Mutable.
When we say that a data type is mutable, we mean that once the elements have been assigned, they can be changed. Conversely, for a data type that cannot be changed, it's referred to as immutable. Lists are mutable, and their elements can be changed.
Indexing a list.
This refers to accessing the elements of a list. There are different methods applied in accessing the elements of a list. The common one is using the operator []. Take a look at the example below.
H= [d, g, k, y, t, I]
H[1]
g
As you can see, we have selected the second element. But there is a slight difference we keyed 1 instead of 2. This is because python indexing begins from 0 instead of 1. Therefore to get the fourth element, you will have to type H[3] on the console.
Again, there are instances that you want to slice out more than one element. For the above analogy, let's say we want to slice out the 3rd and fourth element. Simply type H[2:3] on the python console if you want to select all the other elements except the first element then key in H[2:]. Or if you want to select the other elements except for the last one then key in H[:5].
Negative indexing.
Sometimes we can index the element of a list using negative indexing. How does it differ from the other one? Here is an example of negative indexing
H[-2]
Reversing, copying, and deleting the elements of a list. Reversing a list can be done in the following manner.
H[::1]
Copying the above list to a new variable can be accomplished by
P=H[:]
Note that it is the same as the one used to copy the elements of a string.
To remove the elements of the list, you are better served if you use the methods pop () and remove (). Other methods are del and clear.
List methods.
Here are a few methods that can help you in list manipulation.
Sort (). Used to order a list in an ascending or descending manner.
Count (). Gives the total number of the elements in the list.
Copy (). Copies the elements of a list to another variable.
Reverse (). Changes the order of the list.
Sum (). An inbuilt function that finds the sum of elements in the list
Append (). Adds elements to a list.
Though we tried to be as comprehensive as possible in this article, we hope that it should provide you with all you need to get started with lists. For any queries, our list of homework experts will be glad to help you. Also, contact us for a list of project help
