How to check if a list already contains an element in Python?
<p>i have been working on this for quite a time and my if statement does not seem to have any effect on the code. what I am trying to do is that I want to enter words in a list without repetition.</p>

<pre><code>fname = raw_input("Enter file name: ")
fh = open(fname)
lst = list()
for line in fh:
    line.rstrip()
    words = line.split()
    if lst.count(words) == 0:
        lst = lst + words
    lst.sort()
print lst
</code></pre>

<pre><code>&gt;&gt;&gt; instuff = """one two three
... two three four
... three four five
... """
&gt;&gt;&gt; lst = set()
&gt;&gt;&gt; for line in instuff.split("\n"):
...   lst |= set(line.split())
... 
&gt;&gt;&gt; lst
set(['four', 'five', 'two', 'three', 'one'])
&gt;&gt;&gt;
</code></pre>

python python-2.7 python-3.x