Welcome to if else

Python Style

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by Paula Bannerman dcartist.com

One thing to remember

It's not that bad

It just seems bad

You actually do conditionals (if/else) in your life every day.

If Else statements are like giving choices (based on certain information) to someone who hasn't been exposed to any of it before. It's just it's a computer not a human.

Let's just say you have a light switch set
to off

						light = "off"
						
						
  
							
						  

You tell someone to turn the light on it if the light is off it
would look like this:

						light = "off"
						if light == "off":
							light = "on"
  
							
						  

Now you can tell them if it's off turn it on
or if it's on turn it off:

						light = "on"
						if light == "off":
							light = "on"
						else:
							light = "off"
						  

Let's look at the structure

Basic Structure

						if "this condition is true":
							"do something"
						elif "this other condition is true":
							"do something else "
						else:
							"do this since nothing above is true"
					

Basic Structure

						if "this condition is true":
							"do something"
						elif "this other condition is true":
							"do something else "
						else:
							"do this since nothing above is true"
					

you start with an if and a condition you want to check

Basic Structure

						if "this condition is true":
							"do something"
						elif "this other condition is true":
							"do something else "
						else:
							"do this since nothing above is true"
					

if it's true then do something

Basic Structure

						if "this condition is true":
							"do something"
						elif "this other condition is true":
							"do something else "
						else:
							"do this since nothing above is true"
					

else if something else is true do something else

else if is written as elif

Basic Structure

						if "this condition is true":
							"do something"
						elif "this other condition is true":
							"do something else "
						else:
							"do this since nothing above is true"
					

When nothing in the conditional came out to be true you can use else as a catch all.

nested if

When you need an if else inside another if statement, then you will indent that one on the inside. Like adding a container inside another container.

						if ("this condition is true") :
							do something
						elif ("this other condition is true"):
							if ("this condition is true") :
								do something
							elif ("this other condition is true"):
								"do something else "
							else:
								"do this since nothing above is true"
						else:
							"do this since nothing above is true"
					

Here is another example

						broke = False
						outside_temp = 75
						if broke == True:
							print"FREE office coffee"
						elif outside_temp <= 60:
							print("Hot Coffee from Starbucks")
						else:
							print("Starbucks Ice Coffee")	
					

First we find something to compare, which in this case is being broke and the weather

						broke = False
						outside_temp = 75
						if broke == True:
							print"FREE office coffee"
						elif outside_temp <= 60:
							print("Hot Coffee from Starbucks")
						else:
							print("Starbucks Ice Coffee")	
					

If you are broke, then you are drinking FREE office coffee

						broke = False
						outside_temp = 75
						if broke == True:
							print"FREE office coffee"
						elif outside_temp <= 60:
							print("Hot Coffee from Starbucks")
						else:
							print("Starbucks Ice Coffee")	
					

else if (elif) it's cold outside then you're drinking Hot Coffee from Starbucks

						broke = False
						outside_temp = 75
						if broke == True:
							print"FREE office coffee"
						elif outside_temp <= 60:
							print("Hot Coffee from Starbucks")
						else:
							print("Starbucks Ice Coffee")	
					

else then you're drinking Ice Coffee from Starbucks

Things to remember:

Think in simple terms

If something is true then do this...

Else If (elif) something other than the first statement is true then do this...

Else just do this and call it a day...

Things to remember:

Watch your indentation

for else if it's called elif

just remember you can do tons with if/else

keep practicing using them

The End