Python: Control Flow
Else Statements
(Else Statements) Can be used to execute code when the conditions of an if statement are not met
Boolean Expressions can either be?
- True - False
Except is short for?
Exception
>>>
The prompt when you run Python in your terminal, which you can then use to evaluate simple expressions
Logical Operators
(Boolean Operators) Compare multiple boolean expressions
Relational Operators
(Comparators) Compare two items and return either True or False
Else If Statements
(Elif Statements) Checks another condition after the previous If Statements conditions aren't met
Conditional Statements
(If Statements) Perform different actions depending on whether a specific Boolean evaluates to true or false - They are handled by If Statements
Logical Operators Symbols
- And - (True) And (True) = True - (True) And (False) = False - (False) And (False) = False - Or - (True) Or (True) = True - (True Or (False) = False - (False) Or (False) = False - Not - Not (True) = False - Not (False) = True
Relational Operators Symbols
- Equals: == - Not Equals: != - Greater than: > - Less than: < - Greater than or equal to: >= - Less than or equal to: <=
Describe the control flow in If, Elif, & Else Statements
- First, the if statement is checked - Then each elif statement is checked from top to bottom - Then finally the else code is executed if none of the previous conditions have been met
Which is a boolean expression?
- Today is a weekday - Friday is the best day of the week
What is the difference between = and == in Python?
= is used when defining variables == is used when comparing values
Shell
A command line interface
Boolean Expression
A statement that can either be True or False
Boolean variable
Any variable that is assigned to the values True or False (Bool types)
Try & Except Statements
The First Statement Try will be executed, then if that exception matches the keyword in Except Statement, then the try statement will terminate and the except statement will execute
Bool types
The computer will sign the Bool abbreviation to any boolean data type (True) (False)
Control Flow (OIE)
The order in which instructions are executed
What can Try & Except Statements be used for?
To build error control into your code
Review This Image For Elif Statements
What would happen if all of the elif statements were simply if statements? If you donated $1000.00, then the first three messages would all print because each if condition had been met.