gistfile1.py

# this function takes a number and returns true if the digits of `n` are distinct otherwise returns false
def valid(n):
    return len(set(str(n))) == len(str(n))

# this variable will hold the maximum range found so far
mrange = 0

# this variable keeps track of the start for our range
start = 0
for i in range(10**5):
    
    if valid(i):
        #if i is valid lets mark that range
        print(i)
        # did we found a range greater than the max range found already?
        if mrange < i - start :
            mrange = i - start 
            mstart = start
            mend = i
        start = i

# prints the maximum range, where it starts and where it ends
print(mrange, mstart, mend)