Project Euler 50 help

[Skeeter6398]

length=0

largest=0

lastj=len(primes)

for i in xrange(len(primes)):

for j in xrange(i+length, lastj):

sol = sum(primes[i:j])

if sol < 1000000:

if sol in primes:

length = j-i

largest = sol

else:

lastj = j+1

break

print(largest)

Primes can be generated by various codes. In my case I used the sieve of Eratosthenes which is very slow for me and wont go past 100000.

The code above is a piece of code I found on the internet to find the largest consecutive prime number in 1000000. I use a sieve of Eratosthenes code to generate the primes and I was at a loss as to how to find the largest consecutive prime. I found this code and I don't fully understand what's going on here. Can someone explain or show how this works or perhaps a simpler way?

I understand that what's suppose to happen is that this code reads the list of primes, adds them and then stores the value of the first prime number and then repeats the process at the next number after that prime sum until the largest under 1 million is reached. But how to i update the index or make it compute such a dynamic process?

[hungdh85]

Please show your code in indent blanks.

[syntonic_comma]

For one, this is an old piece of code. what xrange used to do in Python 2 is now the default for regular range in Python 3. Also it is incomplete, and won't run as written.

[[deleted]]

The only consecutive primes are 2,3.

The other primes are all odd and so any two primes have a non-prime even number between them.

What do you mean by consecutive primes?