输出二十到三十以内的所有质数，

import math
def isPrime(q):
    if q <= 1:
        return False
    tmp = int(math.sqrt(q))
    for i in range(2, tmp+1):
        if q % i == 0:
            return False
    return True
x = []
for i in range(20,30):
    if isPrime(i):
        x.append(i)
    else:
        continue
for i in range(len(x)-1):
    print("{} ".format(x[i]),end="")
print(x[-1])