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Comparisons: Auditing the Ledger

Programming isn't just about math; it's about making decisions. To make a decision, the computer needs to compare two values. The result of any comparison is always a Boolean (True or False).

The Comparison Operators​

In Python, we use these symbols to "audit" our data:

  • == Equal to: Checks if two values are the same. (Note: Double == is for comparing; single = is for assigning!)
  • != Not equal to: Checks if two values are different.
  • > Greater than / < Less than
  • >= Greater than or equal to / <= Less than or equal to
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Comparing Strings​


You can also compare text! Python checks strings character by character. Note that capitalization matters: "Python" is not the same as "python".


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Logic Gates: and, or, and not​


Sometimes a single comparison isn't enough. You might need to check if a user has enough money AND if the store is open.


    

  1. and: Returns True only if both sides are True.
    2. 

  2. or: Returns True if at least one side is True.
    3. 

  3. not: Flips the result (True becomes False).
    4. 



[Image of a logic gate truth table for AND, OR, and NOT operations]


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🏆 The Ledger Challenge: The Overdraft Check​


You are writing a script to see if a transaction should be approved.


Task:


    

  1. Create a variable account_balance and set it to 500.
    2. 

  2. Create a variable withdrawal_amount and set it to 600.
    3. 

  3. Create a variable is_overdraft_protected and set it to True.
    4. 

  4. Create a variable can_withdraw. This should be True if:

      

    • The account_balance is greater than or equal to the withdrawal_amount.
      • 

    • OR if is_overdraft_protected is True.
      • 

    

    5. 

  5. Print can_withdraw.
    6. 



Write your code below:


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📚 Deep Dive​





Next Steps​


Now that we can compare values, we can finally tell Python to act on those results using If Statements.