Basics of Python¶

This tutorial covers essential Python concepts, including comments, writing code, and printing information. By the end, you’ll have a clear understanding of these foundational topics.

Comments¶

Comments are an essential part of writing Python code. They allow you to add explanations or notes to your code without affecting its execution.

Single-Line Comments¶

Use the # symbol to create a single-line comment:

In [1]:

# This is a comment

# This is a comment

Multi-Line Comments¶

Use triple quotes (''' or """) to create multi-line comments:

In [2]:

'''
This is also a comment
'''

''' This is also a comment '''

Out[2]:

'\nThis is also a comment\n'

Writing Code¶

In Python, writing code involves creating a set of instructions for the computer to execute. These instructions often include variables, functions, and other Python methods.

Creating a Variable¶

A variable is used to store information for later use:

In [3]:

# Creating a variable, most basic form
name = "Dan"

# Creating a variable, most basic form name = "Dan"

Writing Statements Over Multiple Lines¶

You can split a statement across multiple lines for better readability:

In [4]:

# Writing statements over multiple lines
number = (
    1 + 2
    + 7
)
print(number)

# Writing statements over multiple lines number = ( 1 + 2 + 7 ) print(number)

10

Alternatively, use a backslash (\) to indicate that a statement continues on the next line:

In [5]:

# Writing statements over multiple lines using backslash
new_number = 2 + 3 \
        + 10

print(new_number)

# Writing statements over multiple lines using backslash new_number = 2 + 3 \ + 10 print(new_number)

15

Writing Multiple Statements on One Line¶

You can write multiple statements on a single line using semicolons (;):

In [6]:

# Put multiple statements on one line
num1 = 5; num2 = 3 - 2

# Put multiple statements on one line num1 = 5; num2 = 3 - 2

Printing Information¶

Printing information is essential for debugging and providing program output. Python provides the print() function to display data on the screen.

Printing a String¶

Strings are a sequence of characters enclosed in quotes:

In [7]:

# Printing a string
print("Hello World")

# Printing a string print("Hello World")

Hello World

Common Error: If you forget to enclose text in quotes, Python will throw an error because it will interpret the text as a variable name:

In [8]:

# This does not work because "Hello World" is not a variable or a valid data type
print(Hello World)

# This does not work because "Hello World" is not a variable or a valid data type print(Hello World)

  Cell In[8], line 2
    print(Hello World)
          ^
SyntaxError: invalid syntax. Perhaps you forgot a comma?

Printing a Variable¶

You can print the value of a variable by passing its name to the print() function:

In [9]:

# Printing a variable
word = "Hello World"
print(word)

# Printing a variable word = "Hello World" print(word)

Hello World

Printing Numbers¶

Python can print numbers like integers or floats directly:

In [10]:

# Printing a number
print(3.15)

# Printing a number print(3.15)

3.15

Printing Multiple Values¶

You can print multiple values at once by separating them with commas:

In [11]:

# Printing multiple values
print(3.15, "This is pi", True)

# Printing multiple values print(3.15, "This is pi", True)

3.15 This is pi True

Using Arguments in the print() Function¶

The print() function accepts various arguments to customize its behavior.

Default Behavior of print()¶

By default, print() ends with a newline (\n):

In [12]:

# By default, `end='\n'` means a new line after the print statement
print("This is one line", end='\n')
print("This is another line")

# By default, `end='\n'` means a new line after the print statement print("This is one line", end='\n') print("This is another line")

This is one line
This is another line

Customizing the end Argument¶

You can change the behavior of print() by modifying the end argument:

In [13]:

# Changing the end argument
print("First line", end="---")
print("Second line")

# Changing the end argument print("First line", end="---") print("Second line")

First line---Second line

---

About the Author¶

This tutorial was created by Dan Kornas.

• GitHub: @dankornas
• LinkedIn: Daniel Kornas
• Twitter: @dankornas

If you have any questions or feedback, feel free to reach out or submit an issue in the AI Learning Hub GitHub repository.

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