Remove empty strings from a list of strings

Question

I want to remove all empty strings from a list of strings in python.

My idea looks like this:

while \'\' in str_list:
    str_list.remove(\'\')
         


        

Answer 1

>>> lstr = ['hello', '', ' ', 'world', ' ']
>>> lstr
['hello', '', ' ', 'world', ' ']

>>> ' '.join(lstr).split()
['hello', 'world']

>>> filter(None, lstr)
['hello', ' ', 'world', ' ']

Compare time

>>> from timeit import timeit
>>> timeit('" ".join(lstr).split()', "lstr=['hello', '', ' ', 'world', ' ']", number=10000000)
4.226747989654541
>>> timeit('filter(None, lstr)', "lstr=['hello', '', ' ', 'world', ' ']", number=10000000)
3.0278358459472656

Notice that filter(None, lstr) does not remove empty strings with a space ' ', it only prunes away '' while ' '.join(lstr).split() removes both.

To use filter() with white space strings removed, it takes a lot more time:

>>> timeit('filter(None, [l.replace(" ", "") for l in lstr])', "lstr=['hello', '', ' ', 'world', ' ']", number=10000000)
18.101892948150635