Python doesn’t have a specific data type to represent arrays. The following can be used to represent arrays in Python: If we are using List as an array, the following methods can be used to add elements to it: Example 1: Adding elements to an array using append() function my_input = ['Engineering', 'Medical']
my_input.append('Science')
print(my_input)
Output: ['Engineering', 'Medical', 'Science'] Example 2: Adding elements to an array using extend() function my_input = ['Engineering', 'Medical']
input1 = [40, 30, 20, 10]
my_input.extend(input1)
print(my_input)
Output: ['Engineering', 'Medical', 40, 30, 20, 10] Example 3: Adding elements to an array using insert() function my_input = [1, 2, 3, 4, 5]
print(f'Current Numbers List {my_input}')
number = int(input("Please enter a number to be added:\n"))
index = int(input(f'Enter the index between 0 and {len(my_input) - 1} to add the given number:\n'))
my_input.insert(index, number)
print(f'Updated List {my_input}')
Output:
1. Adding to an array using Lists
2. Adding to an array using array module
If we are using the array module, the following methods can be used to add elements to it:
- By using + operator: The resultant array is a combination of elements from both the arrays.
- By using append() function: It adds elements to the end of the array.
- By using insert() function: It inserts the elements at the given index.
- By using extend() function: It elongates the list by appending elements from both the lists.
Example:
import array s1 = array.array('i', [1, 2, 3]) s2 = array.array('i', [4, 5, 6]) print(s1) print(s2) s3 = s1 + s2 print(s3) s1.append(4) print(s1) s1.insert(0, 10) print(s1) s1.extend(s2) print(s1)
Output:
3. Addition of elements to NumPy array
We can add elements to a NumPy array using the following methods:
- By using append() function: It adds the elements to the end of the array.
- By using insert() function: It adds elements at the given index in an array.
Example:
import numpy # insert function arr1_insert = numpy.array([1, 23, 33]) arr2_insert = numpy.insert(arr1_insert, 1, 91) print(arr2_insert) # append function arr1_append = numpy.array([4, 2, 1]) arr2_append = numpy.append (arr1_append, [12, 13, 14]) print(arr2_append)
Output:
[ 1 91 23 33]
[ 4 2 1 12 13 14]
Conclusion
Thus, in this article, we have implemented possible ways to add elements to an array.
References
- Python add to an array
- Python array Documentation
- Python NumPy Documentation
Note: Python does not have built-in support for Arrays, but Python Lists can be used instead.
Arrays
Note: This page shows you how to use LISTS as ARRAYS, however, to work with arrays in Python you will have to import a library, like the NumPy library.
Arrays are used to store multiple values in one single variable:
Example
Create an array containing car names:
cars = ["Ford", "Volvo", "BMW"]
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What is an Array?
An array is a special variable, which can hold more than one value at a time.
If you have a list of items (a list of car names, for example), storing the cars in single variables could look like this:
car1 = "Ford"
car2 = "Volvo"
car3 = "BMW"
However, what if you want to loop through the cars and find a specific one? And what if you had not 3 cars, but 300?
The solution is an array!
An array can hold many values under a single name, and you can access the values by referring to an index number.
Access the Elements of an Array
You refer to an array element by referring to the index number.
Example
Modify the value of the first array item:
cars[0] = "Toyota"
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The Length of an Array
Use the len() method to return the length of an array (the number of elements in an array).
Example
Return the number of elements in the cars array:
x = len(cars)
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Note: The length of an array is always one more than the highest array index.
Looping Array Elements
You can use the for in loop to loop through all the elements of an array.
Adding Array Elements
You can use the append() method to add an element to an array.
Example
Add one more element to the cars array:
cars.append("Honda")
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Removing Array Elements
You can use the pop() method to remove an element from the array.
You can also use the remove() method to remove an element from the array.
Example
Delete the element that has the value "Volvo":
cars.remove("Volvo")
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Note: The list's remove() method only removes the first occurrence of the specified value.
Array Methods
Python has a set of built-in methods that you can use on lists/arrays.
append() | Adds an element at the end of the list |
clear() | Removes all the elements from the list |
copy() | Returns a copy of the list |
count() | Returns the number of elements with the specified value |
extend() | Add the elements of a list (or any iterable), to the end of the current list |
index() | Returns the index of the first element with the specified value |
insert() | Adds an element at the specified position |
pop() | Removes the element at the specified position |
remove() | Removes the first item with the specified value |
reverse() | Reverses the order of the list |
sort() | Sorts the list |
Note: Python does not have built-in support for Arrays, but Python Lists can be used instead.