import string
import random


def createRandomStrings(l,n,chars=None,upper=False):
    """create list of l random strings, each of length n"""

    names = []
    if chars == None:
        chars = string.ascii_lowercase
    #for x in random.sample(alphabet,random.randint(min,max)):
        
    if upper == True:        
        chars = [i.upper() for i in chars]
    for i in range(l):
        val = ''.join(random.choice(chars) for x in range(n))
        names.append(val)
    return names