This message was edited by streak118 at 2006-5-1 0:1:14

---

ok... Im a tard... somebody, ANYBODY!, please help! tell me what I'm doing wrong? or better yet tell me what to fix and how to? this is a class project. I'm failing this class because Im not grasping programming... and I started with C++ then came to this, HELP!?!

#This program will calculate the time it will take a sound to travel based on
#the matter it is traveling through; air, water, or steel.


def main():

#declare and initialize variables
#AIR as constant
AIR = 1100

#WATER as constant
WATER = 4900

#STEEL as constant
STEEL = 16400

#MenuChoice as string
MenuChoice = " "

#feet as int
#feet = 0

#seconds as int
seconds = 0

#Intro
print "WELCOME TO THE SPEED OF SOUND PROGRAM!!!"
print "I will calculate the time it takes for a souond to travel through"
print "different matter."

#build menu for user to choose from
print "Please choose from the following menu:\n"

print "\tA)\tAir"
print "\tW)\tWater"
print "\tS)\tSteel"

#prompt user for MenuChoice
MenuChoice = raw_input("\nPlease enter your choice here: ")

#prompt user for distance of travel
feet = input("Now, please enter the distance that the sound wave will travel(feet): ")

#calculate time for sound to travel
A = AIR
W = WATER
S = STEEL

if MenuChoice == A:
seconds = feet / AIR
elif MenuChoice == W:
seconds = feet / WATER
else:
MenuChoice == S
seconds = feet / STEEL

#display ETA of the sound

print "\nIt will take", seconds, "second(s) for the sound wave to travel."


ps... I have this indented but it's not showing up on the message board.

: This message was edited by streak118 at 2006-5-1 0:1:14

---

: ok... Im a tard... somebody, ANYBODY!, please help! tell me what I'm doing wrong? or better yet tell me what to fix and how to? this is a class project. I'm failing this class because Im not grasping programming... and I started with C++ then came to this, HELP!?!
:
: #This program will calculate the time it will take a sound to travel based on
: #the matter it is traveling through; air, water, or steel.
:
:

: def main(): 
: 
: #declare and initialize variables 
: #AIR as constant 
: AIR = 1100 
: 
: #WATER as constant 
: WATER = 4900 
: 
: #STEEL as constant 
: STEEL = 16400 
: 
: #MenuChoice as string 
: MenuChoice = " " 
: 
: #feet as int 
: #feet = 0 
: 
: #seconds as int 
: seconds = 0 
: 
: #Intro 
: print "WELCOME TO THE SPEED OF SOUND PROGRAM!!!" 
: print "I will calculate the time it takes for a souond to travel through" 
: print "different matter." 
: 
: #build menu for user to choose from 
: print "Please choose from the following menu:\n" 
: 
: print "\tA)\tAir" 
: print "\tW)\tWater" 
: print "\tS)\tSteel" 
: 
: #prompt user for MenuChoice 
: MenuChoice = raw_input("\nPlease enter your choice here: ") 
: 
: #prompt user for distance of travel 
: feet = input("Now, please enter the distance that the sound wave will travel(feet): ") 
: 
: #calculate time for sound to travel 
: A = AIR 
: W = WATER 
: S = STEEL 
: 
: if MenuChoice == A: 
: seconds = feet / AIR 
: elif MenuChoice == W: 
: seconds = feet / WATER 
: else: 
: MenuChoice == S 
: seconds = feet / STEEL 
: 
: #display ETA of the sound 
: 
: print "\nIt will take", seconds, "second(s) for the sound wave to travel." 
: 

I'll take a closer look a little later, but for now, one quick lesson in Python. The interpreter does not automatically call any "main" function. All you've done here is define a function named "main" and then everything ends. You need to put a call to main after you define it:

def main():
    blah blah blah...

main()

: ps... I have this indented but it's not showing up on the message board.

You need to use the special formatting tags for this board system, [code] and [/code]


infidel

$ select * from users where clue > 0
no rows returned

: def main():
:
: #declare and initialize variables

technically you never "declare" variables in python, you just bind names to values.

: #AIR as constant
: AIR = 1100
:
: #WATER as constant
: WATER = 4900
:
: #STEEL as constant
: STEEL = 16400

I'm sure you know by now, but these aren't true "constants". Python has no such construct.

: #prompt user for distance of travel
: feet = input("Now, please enter the distance that the sound wave will travel(feet): ")

input() is risky because it tries to eval() whatever the user enters so can very easily trigger exceptions. Better to use raw_input and try to convert the value to a decimal.

: #calculate time for sound to travel
: A = AIR
: W = WATER
: S = STEEL

All you've done here is make two names both equal the same value A and AIR are now both references to the same integer object.

: if MenuChoice == A:
: seconds = feet / AIR
: elif MenuChoice == W:
: seconds = feet / WATER
: else:
: MenuChoice == S
: seconds = feet / STEEL

The user entered strings, but here you're checking their input against the value of A. A is different than 'A' in Python.

: #display ETA of the sound
:
: print "\nIt will take", seconds, "second(s) for the sound wave to travel."

Like I mentioned in the other reply, you need to call your main function after defining it.

Ok, so here is what I have come up with:

#This program will calculate the time it will take a sound to travel based on 
#the matter it is traveling through; air, water, or steel. 

# sound propagation "constants"
AIR = 1100 
WATER = 4900 
STEEL = 16400

def main(): 

    #Intro 
    print "WELCOME TO THE SPEED OF SOUND PROGRAM!!!" 
    print "I will calculate the time it takes for a souond to travel through" 
    print "different matter." 

    #build menu for user to choose from 
    print "Please choose from the following menu:\n" 
    print "\tA)\tAir" 
    print "\tW)\tWater" 
    print "\tS)\tSteel" 

    #prompt user for choice 
    choice = ' '
    while choice not in 'AaWwSs':
        choice = raw_input("\nPlease enter your choice here (A, W, S): ")

    #prompt user for distance of travel 
    feet = float(
        raw_input("Please enter the distance (feet) that the sound wave will travel: ")
    )

    #calculate time for sound to travel
    seconds = 0
    if choice in 'Aa': 
        seconds = feet / AIR 
    elif choice in 'Ww': 
        seconds = feet / WATER 
    elif choice in 'Ss': 
        seconds = feet / STEEL 

    #display ETA of the sound 
    print "\nIt will take", seconds, "second(s) for the sound wave to travel."

if __name__ == '__main__':
    main()

infidel

$ select * from users where clue > 0
no rows returned

thank you so much for your help! unfortunantly the teacher never taught us the __whatever__ codes so if I used them it would look suspicious... lol... here's what I ended up with minus input validations..

#This program will calculate the time it will take a sound to travel based on
#the matter it is traveling through; air, water, or steel.


def main():

    #declare and initialize variables
    #AIR as constant
    AIR = 1100
    
    #WATER as constant
    WATER = 4900
    
    #STEEL as constant
    STEEL = 16400

    #MenuChoice as string
    MenuChoice = " "

    #feet as int
    #feet = 0

    #seconds as int
    seconds = 0

    #Intro
    print "WELCOME TO THE SPEED OF SOUND PROGRAM!!!"
    print "I will calculate the time it takes for a souond to travel through"
    print "different matter."

    #build menu for user to choose from
    print "Please choose from the following menu:\n"
    
    print "\tA)\tAir"
    print "\tW)\tWater"
    print "\tS)\tSteel"

    #prompt user for MenuChoice
    MenuChoice = raw_input("\nPlease enter your choice here: ")
    
    #prompt user for distance of travel
    feet = input("Now, please enter the distance that the sound wave will travel(feet): ")

    feet = float(feet)

    #calculate time for sound to travel
    
    if MenuChoice == "A":
        seconds = feet / AIR
    elif MenuChoice == "W":
        seconds =  feet / WATER
    else:
        MenuChoice == "S"
        seconds = feet / STEEL
        
    #display ETA of the sound
    
    print "\nIt will take", seconds, "second(s) for the sound wave to travel."

again thank you so much for helping, I'll need more help between now (may 1st, 10:10pm est) and tomorrow 5pm with three other programs I have to build... I hope you can help some more.