What am I missing for my python program to run?

def display$\_$menu$()$:

print$("$Welcome to Sammy's Pizzas"$)$

print$("$What size pizza would you like?"$)$

print$("1.$ Small Cheese Pizza$-$ $$8")$

print$("2.$ Medium Cheese pizza$-$ $$10")$

print$("3.$ Large Cheese Pizza$-$ $$12")$

def get$\_$pizza$\_$size$()$:

while True:

try:

choice$=$ int$($input$("$Enter the number of what size you would like: $"))$

if choice in $[1,2,3]$:

return choice

else:

print$("$Invalid choice. Please use $1,2,$ or $3")$

except ValueError:

print$("$Invalid input please try again"$)$

def get$\_$toppings$()$:

print$("$Each topping is $$1$ more"$)$

print $("$Your toppings choice is

$1.$Sausage

$2.$ Pepperoni

$3.$Olives."$)$

toppings $=\{"$pepperoni$"$: $0,$ "sausage": $0,$ "olives": $0\}$

while True:

try:

choice$=$ int$($input$("$Enter the number of your desired topping. $"))$

if choice in $[1,2,3]$:

print $($f$"$Great you chose $\{$choice$\}.")$

return choice

else:

print$("$Invalid choice. Please use $1,2,$ or $3")$

except ValueError:

print$("$Invalid input please try again"$)$

def calculate$\_$cost $($size$,$ toppings$)$:

base$\_$prices $=\{1$:$8,2$:$10,3$:$12\}$

cost $=$ base$\_$prices$[$size$]$

for topping in toppings.values$()$:

cost $+=$ topping

return cost

def main$()$:

display$\_$menu$()$

size $=$ get$\_$pizza$\_$size$()$

toppings $=$ get$\_$toppings$()$

total$\_$cost $=$ calculate$\_$cost$()$

print$($f$"$Your total cost is $$\{$total$\_$cost:$2$f$\}")$

if $\_\_$name$\_\_=="\_\_$main$\_\_"$:

main$()$