Петър обнови решението на 01.05.2012 15:06 (преди почти 12 години)
+from math import sqrt
+
+
+def is_prime(number):
+ '''
+ Check whether the number is prime.
+
+ Keywortd arguments:
+ number -- the number who will be checked
+
+ Return: bool
+ '''
+ return all([number % divisor for divisor
+ in range(2, int(sqrt(number)) + 1)])
+
+
+def primes():
+ '''
+ Generator for a prime numbers.
+ '''
+ number = 2
+ while True:
+ if is_prime(number):
+ yield number
+ number += 1
+
+
+def prime_divisors(number):
+ '''
+ Gets all prime divisors of the number.
+
+ Keywortd arguments:
+ number -- the number whose prime divisors will be searched
+
+ Return: list
+ '''
+ divisors = []
+ for prime in primes():
+ while number % prime == 0:
+ divisors.append(prime)
+ number /= prime
+ if number == 1:
+ return divisors
+
+
+def semiprimes():
+ '''
+ Generator for a semi-prime numbers.
+ (semi-primes - numbers with exacly 2 prime divisors)
+ '''
+ number = 4
+ while True:
+ if len(prime_divisors(number)) == 2:
+ yield number
+ number += 1