My journey through learning Python: Day 4 to 5

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In this article, we'll talk about the random Python module, about lists and loops. So, take a seat, grab your cup of tea and here we go.

Day 4: Randomisation and Python Lists

Randomisation

Randomisation is a powerful concept in computer programming that allows for the generation of unpredictable and diverse outcomes. By introducing randomness into your programs, you can add a layer of complexity and variety that can make them more interesting and useful. In Python, randomisation can be achieved using the built-in library random.

Here is an example of how to generate a random number in Python:

import random

# Generate a random number between 1 and 10
random_number = random.randint(1, 10)

# Print the random number
print(f'The random number is: {random_number}')

In this example, we first import the random module using the import statement. We then use the randint function from the random module to generate a random integer between 1 and 10 (inclusive). Finally, we print the random number using the print statement.

Each time we run this code, a different random number between 1 and 10 will be generated and printed to the console.

Lists

Lists are an essential data structure in Python, providing a way to store and manipulate collections of data. A list is an ordered collection of elements, which can be of any data type - integers, strings, floating-point numbers, or even other lists (called nested lists).

Creating a list in Python is simple. You can define a list by enclosing a comma-separated sequence of values in square brackets, like this:

my_list = [1, 2, 3, 4, 5]

You can also create an empty list using square brackets with no values inside:

empty_list = []

Once you have created a list, you can access individual elements using their index, which is their position inside the list. In the introduction, we said that a list is ordered. That means that the elements are in a certain order in the list and that order doesn't change.

Note: In Python, lists are zero-indexed, meaning that the first element has an index of 0, the second element has an index of 1, and so on. You can access an element by specifying its index in square brackets, like this:

first_element = my_list[0]
second_element = my_list[1]

You can also modify the elements of a list by assigning a new value to a specific index, like this:

my_list = [0, 1, 2]
my_list[0] = 100
print(my_list)
# [100, 1, 2]

Lists also provide a range of built-in methods for manipulating their contents. For example, you can add elements to a list using the append() method:

my_list = [0, 1, 2]
my_list.append(6)
print(my_list)
# [0, 1, 2, 6]

Note that the appened element is at the end of the list.

You can also remove elements using the remove() method:

my_list = [0, 1, 2]
my_list.remove(0)
print(my_list)
# [1, 2]

You can see all the methods about lists in the Python documentation: right here

Day 5: Python for Loops

A for loop in Python is a control flow statement that allows you to iterate over a sequence (such as a list, tuple, or string) or other iterable objects (such as range objects) and execute a block of code for each item in the sequence.

Here is the basic syntax of a for loop in Python:

for variable in sequence:
    # code block to be executed

In the above code, variable is a variable that is updated at each iteration of the loop, and sequence is the sequence or iterable object over which the loop is iterating.

Here is an example of a for loop that iterates over a list of numbers and prints out each number:

numbers = [1, 2, 3, 4, 5]
for num in numbers:
    print(num)

This would output:

1
2
3
4
5

You can also use the built-in range() function to generate a sequence of numbers to iterate over. For example:

for i in range(5):
    print(i)

This would output:

0
1
2
3
4

Note that just like list indexes, the range function starts at 0, unless you specifies the starting point, like :

for i in range(1, 5):
    print(i)

This one would output:

1
2
3
4

In the next article, we'll talk about functions, a big piece of Python! So, stay with me and see you soon. 🐍