def randomstr(num):
    randomstr = ''
    for i in range(num):
        randomstr = (randomstr + random.choice('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'))
    return randomstr
def randomstr(num):
    randomstr = 
    for i in range(num):
        randomstr = (randomstr + random.choice('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'))
    return randomstr