#23 Array in Python |Array values from User in Python | Search in Array

In this lecture we will learn:
What is an array in Python?
Importing the array module
Different functions used with arrays
Fetching all values of an array
Indexing in an array
How to create an empty array?
How to create an array through user input?
Array creation by taking the values from a user
How to search an element in an array?
Function used to get the index value of an element in python

#1
Array is almost to list with one difference that all the values that are present should be of the same type.
In python, arrays do not have fixed sizes, they can be expanded or shrunk.
We need to import a module known as an array to use the arrays in python.
e.g., import array as arr
At the time of importing the module, you can specify the functions that you will use in the code.
You can also use (*) in place of defining each function separately. * indicates all functions have to be included.
In an array, we have to specify things:
1. Type
2. Value
By changing the type of a value, the size of the allocated memory is also changed.
We have to use the TypeCode to define its type in an array.

#2
Normal integers go from a negative range to a positive range.
Unsigned integers are used when you do not want to store negative values.
A numeric variable is signed if it can represent both positive and negative numbers.
A value will be unsigned if it can only represent non-negative numbers (zero or positive numbers).

#3
buffer info() function gives you the size of an array.
buffer info() function returns two things: an address and the size of an array.
typecode () function is used to return the type code of an array with which you are working.
append() method is used to add a value in an integer.
remove() method is used to remove a value from an array.
reverse() method is used to reverse the order of value of an array.

#4
In python, arrays also support indexing. Values can be fetched through index values.
Array indexing is the same as accessing an array element.
You can access an array element by referring to its index number.
len() function is used to get the length or size of an array.
len() function returns the number of elements present in the array.
We can use both for loop and while loop in different ways to fetch the values of an array.
We can also assign all values of a previous array into a new array one by one.

#5
We can also create a blank array and can take the values for it from the user.
First, we have to take the length of an array from the user.
input() function takes the value in the form of a string, so we have to change it into an integer using int().
We can run a loop in a range of length of an array given by the user. At each iteration, we can take a value to be inserted in an array.
append() is a function that is used to add a value or an element in an array.

#6
To search for any value in an array or to check the index number at which the value is present, we need to increment the value of an iterator variable in every iteration.
When the condition of comparison gets true, we stop the loop to iterate further and print the value of an iterator variable.
The iterator variable will return an index number of the value, you have searched for.

#7
index() function can also be used to get the index number of a value in an array.