added sieve of eratosthenes in python

02. Algorithms/06. Number Theory/Sieve Of Eratosthenes/Sieve_Of_Eratosthenes.py

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+from math import ceil
+from math import sqrt
+
+def sieve_of_eratosthenes(n):
+is_prime = [True for i in range(n + 1)]
+
+for i in range(2, ceil(sqrt(n))):
+if is_prime[i]:
+for j in range(i ** 2, n + 1, i):
+is_prime[j] = False
+is_prime[0] = False
+is_prime[1] = False
+
+primes = []
+for number in range (n + 1):
+if is_prime[number]:
+primes.append(number)
+return primes
+
+num = 100
+print("primes lower than ", num, ": ", sieve_of_eratosthenes(num))