[Tutor] please help - stuck for hours
Wayne Werner
waynejwerner at gmail.com
Thu Nov 17 23:53:59 CET 2011
On Thu, Nov 17, 2011 at 4:32 PM, ADRIAN KELLY <kellyadrian at hotmail.com>wrote:
>
> thanks very much, great response really really appreciated it and now i
> understand. i hate to ask again but can you see why it won't print the
> 'enter and amount over 50' in the right place??
>
Computers are unfailingly stupid machines. They will do whatever wrong
thing you tell them to do every single time.
> <snip>
> def main():
> amount=0
> while amount<50:
> amount = input('how much do you want to change:')
> print 'enter an amount over €50: '
> else:
> total=exchange(amount)
> print 'Your exchange comes to: ',total
>
Sometimes it helps writing out the logic in steps before you translate it
to code. In this case my guess is that these are the steps you want:
1. Get a value from the user (you're still using input - stop that, it's
dangerous! input is only a good function in 3.x where it replaces
raw_input)
2. If the value is less than 50, tell the user to enter an amount > 50
and repeat step 1
3. Otherwise, exchange the amount and display that.
Right now, these are the steps that you're doing:
1. Get a value from the user
2. Display the error message
3. If the value is < 50, go to 1
4. exchange the amount
5. display the amount.
HTH,
Wayne
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