Part 3: Loops and Conditional Functions

Topic 1: Loops

Basic Structure of a "for" loop:

  1. for (dummy variable) in Object:
  2. Do thing here
A dummy variable is anything you want to use to replace the object. For python to recognize the for loop you will need to indent the statements within the for loop.

for x in States, Print x

Basic Structure of a "while" loop:

  1. while Condition:
  2. Do thing here

We need to have at least one condition to implement the loop and make sure we don't get an infinite (or endless) loop. Be sure to indent the statements to repeat in the loop. 

Sometimes while loops are more necessary and sometimes for loops are more necessary. In general, for loops are used when you know exactly how many times you plan to run a loop; a while loop is used when the number of iterations is uncertain.

Topic 2: Conditional Statements

An if statement is a conditional statement that does something if the condition you set is met.

Basic Structure of a conditional statment:

if Condition:

    do thing here

elif Condition

    do thing here


    do thing here


An if/else statement can have many parts. If the first condition isn’t met Python moves on to the elif(else if) statement and if no statement works. Indents are still required to use if statements.


Topic 3: Functions

Basic Structure of a function:

def functionName(parameter1, parameter2, ...):

      do things here


The parentheses contain what are called parameters. These are the variables that are input into the function that contribute to the final output. Parameters are not always required; depending on the function, they can include anything from integers and strings to other functions. Let us create a simple area calculating function to get used to the syntax.

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