premier.py

from math import sqrt

def premier(a):

    # si == 1 ou ==2
    if(a == 1 or a== 2):
        return True
    # si pair
    elif(a % 2 == 0):
        return False
    else:
        if (int(sqrt(a)) == sqrt(a)):
            return False
        
        for k in range(3, int(sqrt(a)+1), 2):
            if a % k == 0:
               return False
        
        return True 
    # autre

assert premier(1) == True
assert premier(2) == True
assert premier(4) == False
assert premier(9) == False

assert premier(3) == True
assert premier(20) == False
assert premier(23) == True
assert premier(6067) == True