for a in range (3,10):
if ((a%3==0) or (a%5==0)):
This is a simple script that should be simple to understand.
import is python's means of accessing functions in external files.
The for loop structure in python is a bit different compared to Basic or C/Java. Range(0,n) makes a list of numbers from 0 to n-1. i.e. n is not included.
For a in <list> will iterate through the list, and the variable "a" will represent each element in that iteration.
Here's my solution to Euler 2:
#By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.
if (not num1%2) and num1 < 4000000:
if (not num2%2) and num2 < 4000000:
This is another fairly basic algorithm. No need to worry about memory and fairly simple checks. Fibonacci explodes fairly quickly so the number of iterations here is low - under 20.
That's all for now. Both quite simple. Problem 3 gets much more interesting.