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Arrays.py
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Arrays.py
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# Python Arrays
# *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"]
# 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
# Get the value of the first array item:
x = cars[0]
# Example
# Modify the value of the first array item:
cars[0] = "Toyota"
# 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)
# *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.
# Example
# Print each item in the cars array:
for x in cars:
print(x)
# 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")
# Removing Array Elements
# You can use the pop() method to remove an element from the array.
# Example
# Delete the second element of the cars array:
cars.pop(1)
# 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")
# *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.
# Method Description
# 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: Methods of Arrays & Lists Are Exactly Same
# *Note: Python does not have built-in support for Arrays, but Python Lists can be used instead.