[Tutor] Need help w/ a for loop
Kent Johnson
kent37 at tds.net
Thu Oct 23 13:21:43 CEST 2008
On Thu, Oct 23, 2008 at 12:09 AM, Monte Milanuk <monte at milanuk.net> wrote:
> def main():
> print "This program will approximate the value of pi"
> print "to a degree determined by the user. "
> print
>
> # get the value of n from the user
> n = input("How many terms do you want me to sum? ")
> print
>
> # create a loop from 1 to n+1, odd)
Here you should initialize a variable to hold the sum. 'sum' is not a
good name because it is the name of a built-in function. 'total' is
better.
> for i in range(1,n + 1,2):
Note that this loop has n/2 steps, not n.
> # each term is '4/i' as it steps thru the loop starting with 1
> x = 4 / i
Do you know about integer vs float division? What is the difference
between 4/9 and 4.0/9?
> # output the sum - convert it to a float just in case
If it isn't already a float you won't have a very good estimate of pi.
Kent
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