Python Arrays

Python arrays are a special variable that have the ability to hold more than one value. For instance, if were a list of of car models, those models could be stored into single variables. The array can hold a fix number of elements and these elements must be the same type (string, integer). When creating an array, each item that is stored is referred to as an element and the location of each element is referred to as an index.

Python Array Methods

Python Array Creation

Creating an array is similar to creating a list in Python, which can be easily done by using square brackets and surrounding the values with quotes if needed (strings).

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Python Array Access

In order to access the elements in the array, the index number will be executed to refer to the array element.

Array Example 1

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Array Example 2

The below is accessing the list by using random and randomly picking an element from the list to call in the print statement.

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Python Change List Item

This is similar to the list access, but we will create a variable with the list item referencing the index number and provide the update.

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Python List Looping

Within an array, a loop can print out each element that is in the array using a for loop.

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Python Array Validating Element

Python array element validation will determine if an element is in the array by using the keyword, in.

if…else Example 1

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if…else Example 2

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Python Array Length

The internal method, len() will determine the length(element count) of an array. Notice when we updated the array we started with 0, but with the length, the count will start with 1 and not 0.

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Python Adding Array Elements

The internal  method, append() will add a specified item to the end of an array. The append() method  can only take exactly one argument. In the below example, we will add 5 tech companies to the array in 5 separate append() statements.

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Python Insert Item

The internal  method, insert() will add a item to the index number specified.

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Python Item Removal

There are multiple methods to remove an item from a list. Below are the methods we will cover:

• remove()
• pop()
• del()

remove()

The method remove() will remove the specified element in the array.

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pop()

The method pop() will remove the specified element by specifying the index number. However, if the index number is not specified this method will remove the last element in the array.

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del

The method del will remove the specified item by the specified index number.

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Python List Copying

Python list copying can be executed by using the copy() method or the list() method. In Python, copying a list by reference a variable1 to variable2 will only reference variable1.

copy() method

The copy() method produces an identical copy of the initial list.

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