How to get an approx sum of an infinite series in python.

[Fuugie]

I'm having trouble writing a program that will get me an approximate sum of an infinite series.

This is my code:

def factorial(n):
     if n == 0:
         return 1
     else:
         return n * factorial(n-1)

if 

print
raw_input()

This is the equation i have to use:


How would I get this to finish solving for 'e' ?

[bvdet]

You got the factorial part. I am using a list comprehension in the code below to determine the value of e.

>>> def factorial(n):
...     if n == 0:
...         return 1
...     return n*factorial(n-1)
... 
>>> def calc(u):
...     return sum([1.0/factorial(i) for i in range(0, u+1)])
... 
>>> calc(100)
2.7182818284590455
>>>

[Fuugie]

how would i have it print the solution afterwards?

[bvdet]

If you are using Python 2.X:

print calc(number)

Perhaps you should spend some time perusing a Python beginner's guide.

[Fuugie]

I didn't mean like that, i know how to get something to print. I was asking about the solution to the problem. I still can't get this to work correctly.

Here is my code:

terms = raw_input('How many terms? ')

def factorial(n):
     if n == 0:
         return 1
     else:
         return n * factorial(n-1)
     
def calu(u):
     return sum([1.0/factorial(n) for i in range(0, u + 1)])


print (calu)
raw_input()

[bvdet]

Try this:

value = calu(int(terms))
print (value)

You also have a problem in calu(). Variable n should be variable i.

I recommend you study this documentation on Python scope rules.

[Fuugie]

Why does the variable have to be i instead of n?

[bvdet]

Variable n is local to the scope of function factorial() and is not defined in the scope of calu(). In addition to that, look at the following:

>>> sum([i for i in range(5)])
10
>>> n = 100
>>> sum([n for i in range(5)])
500
>>> range(5)
[0, 1, 2, 3, 4]
>>>

As I stated in my previous post: I recommend you study this documentation on Python scope rules.

[Fuugie]

Alright. Thank you so much for the help bvdet!