Lesson 3

Understanding and Applying Python Comparison Operators for Beginners

Introduction and Topic Overview

Hello, Stellar Navigator! Today, we're diving into Python Comparison Operators. These operators allow us to compare two values, yielding a boolean result — True or False. Our goal is to understand these operators and become comfortable with operator chaining. Are you ready? Let's delve in!

Understanding Python Comparison Operators

Comparison operators in Python are used to compare two values and yield a boolean outcome. The comparison operators in Python are:

  • Equal to (==)
    • Note that = and == are two different operators - the former is an assignment operator (e.g., variable = 2), and the latter is the equality comparison.
  • Not equal to (!=)
  • Greater than (>)
  • Less than (<)
  • Greater than or equal to (>=)
  • Less than or equal to (<=)

For instance, if you have $20 and want to buy a $15 toy, see the example below:

Python
1price_of_toy = 15 2money_in_hand = 20 3 4# Compare two variables and assign the result to a new variable 5can_buy_toy = money_in_hand >= price_of_toy 6print(can_buy_toy) # Prints: True

Here, we use the >= comparison operator to check if we have enough money to buy the toy — the answer is True! Note how we assigned the result of the comparison to a new variable - can_buy_toy.

Deep Dive into Python Comparison Operators

Let's investigate these operators further with some coding examples:

Python
1print(10 == 10) # True - because 10 is indeed equal to 10 2print(10 > 10) # False - because 10 isn't greater than 10 3print(10 < 10) # False - because 10 isn't less than 10 4print(10 != 10) # False - because 10 isn't unequal to 10 5print(10 >= 10) # True - because 10 is equal to 10 6print(10 <= 10) # True - because 10 is equal to 10

The result of these comparison operators is a boolean value — True or False.

Expanding the Horizons - Operator Chaining

Python allows us to chain together comparisons. This technique can be handy when we want to perform multiple comparisons in a single line:

Python
1book_pages = 150 2is_desired_book = 100 < book_pages < 200 # Check if the number of pages is between 100 and 200, exclusive 3print(is_desired_book) # Prints: True

In this case, we've used operator chaining to verify whether a book that's 150 pages long falls within the range of 100 to 200 pages. The answer is True!

In-Depth Examples and Scenarios

Let's apply comparison operators to numbers and strings:

Python
1# Numbers 2number = 5 3print(number == 5) # True - 5 is equal to 5 4print(number > 3) # True - 5 is greater than 3 5print(number < 3) # False - 5 is not less than 3 6print(number >= 5) # True - 5 is equal to 5 7 8# Strings 9fruit = "apple" 10print(fruit == "apple") # True - "apple" is the same as "apple" 11print(fruit != "banana") # True - "apple" is not "banana" 12print(fruit < "banana") # True - "apple" comes before "banana" in the dictionary

In Python, strings are compared alphabetically. To provide a real-life example - imagine both words in the word dictionary, which one will go first there? This word is less than the other one!

Lesson Summary

Congratulations! Today, we navigated through the Python comparison operators and the concept of operator chaining. We saw them in action with some practical examples. Our upcoming exercises provide numerous opportunities for you to practice these concepts. Remember, each correct solution brings you closer to mastering Python. Happy coding!

Enjoy this lesson? Now it's time to practice with Cosmo!

Practice is how you turn knowledge into actual skills.