# Sieve of Eratosthenes in Python
**URL:** https://discourse.processing.org/t/sieve-of-eratosthenes-in-python/37866
**Category:** Processing.py
**Created:** [July 7, 2022, 7:12am UTC](https://discourse.processing.org/t/sieve-of-eratosthenes-in-python/37866 "2022-07-07T07:12:27Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@shivambhatele](https://discourse.processing.org/u/shivambhatele)
#### Post date: [July 7, 2022, 7:12am UTC](https://discourse.processing.org/t/sieve-of-eratosthenes-in-python/37866/1 "2022-07-07T07:12:28Z")
Hello All, I working on a python project and I am confused sieve of eratosthenes coding problem. The problem statement is Given a number n, print all primes smaller than or equal to n. It is also given that n is a small number.
A prime number is a number that is divisible by only two numbers – themselves and 1
Example:
Input: n =10
Output: 2 3 5 7
I have taken this code reference from [here](https://www.interviewbit.com/blog/sieve-of-eratosthenes/). Can anyone explain me with the help of this code, how sieve of eratosthenes program works? or explain with another example?
```auto
def isPrime(n):
# Corner case
if n <= 1 :
return False
# check from 2 to n-1
for i in range(2, n):
if n % i == 0:
return False
return True
# Function to print primes
def printPrime(n):
for i in range(2, n + 1):
if isPrime(i):
print(i, end = " ")
```
---
### Author:  [@tabreturn](https://discourse.processing.org/u/tabreturn)
#### Post date: [July 7, 2022, 9:28am UTC](https://discourse.processing.org/t/sieve-of-eratosthenes-in-python/37866/2 "2022-07-07T09:28:58Z")
This is a Processing forum, so here’s something that uses Processing.py / Python Mode, that rearranges the example in a way you may find easier to comprehend –
```python
# set framerate to 1 frame every 2 seconds
def setup(): frameRate(0.5)
def draw():
# loop through all of the numbers between 2 and framecount
for i in range(2, frameCount):
# divide the framecount by every number from 2 up to framecount
if frameCount % i == 0:
# if the remainder of any division is zero,
# the framecount divides evenly by i,
# therefore it is not a prime number
print(
'{} is not prime because it divides evenly into {}'.format(frameCount, i)
)
# exit the loop immediately and start again on the next frame
return
# if the loop didn't exit, the framecount is a prime number
print('{} is prime'.format(frameCount))
```
---
### Author:  [@javagar](https://discourse.processing.org/u/javagar)
#### Post date: [July 7, 2022, 10:11am UTC](https://discourse.processing.org/t/sieve-of-eratosthenes-in-python/37866/3 "2022-07-07T10:11:10Z")
You may find this discussion interesting, which is on [Python Software Foundation Discourse](https://discuss.python.org/):
> **[Sieve of Eratosthenes in Python](https://discuss.python.org/t/sieve-of-eratosthenes-in-python/17130/)**
>
> Hello All, I working on a python project and I am confused sieve of eratosthenes coding problem. The problem statement is Given a number n, print all primes smaller than or equal to n. It is also given that n is a small number. I am trying to solve...