How can I make it so this code loops?

#This script helps users reduce their vehicle greenhouse gas emissions by recommending strategies.

#Inputs: Current vehicle emissions data $($in grams per kilometer$).$

#Outputs: Recommended strategies and potential emission savings.

def calculate$\_$emission$\_$savings$($current$\_$emissions, strategy$\_$factor$)$:

#Calculate potential emission savings based on current emissions and strategy factor.

#Parameters:

#current$\_$emissions $($float$)$: The current emissions in grams per kilometer.

#strategy$\_$factor $($float$)$: The reduction factor for the chosen strategy.

#Returns:

#float: Potential emission savings.

return current$\_$emissions $*$ strategy$\_$factor

def main$()$:

print$("$Welcome to the Greenhouse Gas Emission Reduction Tool"$)$

try:

current$\_$emissions $=$ float$($input$("$Enter your vehicle's current emissions $($grams$/$km$)$: $"))$

strategies $=\{$

"Carpooling": $0\mathrm{.}20,$ # $20\%$ reduction

"Public Transport": $0\mathrm{.}30$ # $30\%$ reduction

$\}$

print$("$

Available Strategies:"$)$

for strategy in strategies:

print$($f$"-\{$strategy$\}")$

choice $=$ input$("$

Choose a strategy $($Carpooling$/$Public Transport$)$: $").$strip$()$

if choice in strategies:

savings $=$ calculate$\_$emission$\_$savings$($current$\_$emissions, strategies$[$choice$])$

print$($f$"$

By adopting $\{$choice$\},$ you can reduce your emissions by $\{$savings:$\mathrm{.}2$f$\}$ grams$/$km$.")$

else:

print$("$Invalid choice. Please choose a valid strategy."$)$

except ValueError:

print$("$Invalid input. Please enter a numeric value for emissions."$)$

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

main$()$