import re

s_l = ['abcabcabcabc','defdef.','sssssss','def','def,','xyzabc,','efgdefefg']

for idx, str_item in enumerate(s_l):
    if re.match(r'^(?=abc|def)(?!.*(?:xyz|efg)).{1,10}$(?<![,.])', str_item): #find length of str smaller than 10
        print(idx, "True")
    else:
        print(idx, "False")