This simple filtering can be achieved in many ways with Python. The best approach is to use "list comprehensions" as follows:
>>> lst = ['a', 'ab', 'abc', 'bac']
>>> [k for k in lst if 'ab' in k]
['ab', 'abc']
Another way is to use the filter function. In Python 2:
>>> filter(lambda k: 'ab' in k, lst)
['ab', 'abc']
In Python 3, it returns an iterator instead of a list, but you can cast it:
>>> list(filter(lambda k: 'ab' in k, lst))
['ab', 'abc']
Though it's better practice to use a comprehension.
[x for x in L if 'ab' in x]
Tried this out quickly in the interactive shell:
>>> l = ['a', 'ab', 'abc', 'bac']
>>> [x for x in l if 'ab' in x]
['ab', 'abc']
>>>
Why does this work? Because the in operator is defined for strings to mean: "is substring of".
Also, you might want to consider writing out the loop as opposed to using the list comprehension syntax used above:
l = ['a', 'ab', 'abc', 'bac']
result = []
for s in l:
if 'ab' in s:
result.append(s)
# To support matches from the beginning, not any matches:
items = ['a', 'ab', 'abc', 'bac']
prefix = 'ab'
filter(lambda x: x.startswith(prefix), items)
mylist = ['a', 'ab', 'abc']
assert 'ab' in mylist
Source: Stackoverflow.com