['aaauucso', 'eeaaauows', 'jjtettowrue']

  
>>> lst = ['aaauucso', 'eeaaauows', 'jjtettowrue']
>>> out = list(filter(lambda i: 'aaau' in i, lst))
>>> out
['aaauucso', 'eeaaauows']
>>> 
>>> lst = ['aaauucso', 'eeaaauows', 'jjtettowrue']
>>> out = [i for i in lst if 'aaau' in i]
>>> out
['aaauucso', 'eeaaauows']
>>>