[Tutor] Advise...

[Jacob S.]

Thanks everyone!

Kent started the suggestion of making a code object, but everyone else seems 
to have worked their way to it.
Beautiful! I only have to call exec once, and it cuts down time 
considerably.

Here is the new code.
Jacob Schmidt

Please remind me if I've forgotten anything.

### Start ###################
from __future__ import division
from math import *
import psyco
psyco.full()

def reimannsum(fofx,x,max1):
    total = 0
    step = 1e-5
    exec "def f(x): return %s" % fofx
    while x <= max1:
        total = total+f(x)
        x = x+step
    return abs(total*step)

fofx = raw_input("What is the function? ")
minimum = raw_input("What is the minimum? ")
maximum = raw_input("What is the maximum? ")
minimum = float(minimum)
maximum = float(maximum)
print reimannsum(fofx,minimum,maximum)
#### End ##############################

>> If the user must be able to enter in the function, then it would be
> better
>> to evaluate this once and turn it into some sort of function that
> you can
>> call inside the loop (it's the eval that is so expensive).  How to
> do that
>> depends a lot on how complex the possible functions can be (if
> they'll only
>> include 'x*+/-' and numbers, for example, it's not so tricky).
>
> exp = raw_input('Type expression')
> func = eval('lambda x: " + exp)
>
> print func(42)
>
>
> etc...
>
> Or if you really can't grokm lambda:
>
> exec('def func(x): return " + exp)
>
> should do the same...
>
> Alan G.
>
>
>