Pandigital prime

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def is_prime(n):
    ''' 
    
    Use the prime algorithm to judge whether a number is prime
    Time complexity is O(sqrt(n)).
    
    '''
    q = 2
    while q * q <= n:
        if n % q == 0:
            return False
        q += 1
    return True


def pandigital_prime():
    ''' 
    
    Use a trick to get the all pandigital numbers
    with the number permutations the all pandigital numbers
    count is 46233.so we can limit the range to avoid the 
    execute too many times
    
    >>> pandigital_prime()
    >>> 7652413
    '''
    ans = 0
    import itertools
    for j in range(2, 10):
        pandigital = [
            "".join(map(str, i)) for i in itertools.permutations(list(range(1, j)))
        ]
        for n in pandigital:
            if is_prime(int(n)):
                ans = max(ans, int(n))
    return ans