Temperature Converter

#Enter temperature in Farenheit
try:
    InputTempF= float(input("Enter a temperature in Farenheit: "))
except ValueError:
    print("That wasn't a float!")

#Converts user-input Fahrenheit to Celsius.
InitF = InputTempF #This add-on to the global function allows for user input.
def return_celsius(): #This is a global function to return Celsius.
    print((InitF - 32)/1.8)
return_celsius()

#Change 0C to F:
InitC = 0
#Global function to convert Celsius to Farenheit.
def return_farenheit():
    print((InitC*1.8)+32)
return_farenheit()
#Change 100C to F:
InitC = 100
return_farenheit()

#Change 40F to C:
InitF = 40
return_celsius()

#Change 80F to C:
InitF = 80
return_celsius()