ProjectEuler#38 Pandigital multiples

#Take the number 192 and multiply it by each of 1, 2, and 3:

#    192 x 1 = 192
#    192 x 2 = 384
#    192 x 3 = 576

#By concatenating each product we get the 1 to 9 pandigital, 192384576.
#We will call 192384576 the concatenated product of 192 and (1,2,3)

#The same can be achieved by starting with 9 and multiplying by 1, 2, 3, 4,
#and 5, giving the pandigital, 918273645, which is the concatenated product
#of 9 and (1,2,3,4,5).

#What is the largest 1 to 9 pandigital 9-digit number that can be formed as
#the concatenated product of an integer with (1,2, ... , n) where n > 1?

def is1To9Pandigital(nStr):
    if '0' in nStr or len(nStr) != 9:
        return False
    count = 0
    for i in range(1,10):
        if str(i) in nStr:
            count +=1
    if count == 9:
        return True
    else:
        return False

largestProduct = 0

for i in range(1,1000000): #since n>2, max number should have 5-digits max
    productStr = ''
    for j in range(1,10):
        productStr += str(i*j)
        if len(productStr) >= 9:
            break
    if len(productStr) == 9 and is1To9Pandigital(productStr)\
       and int(productStr) > largestProduct:
        largestProduct = int(productStr)