run python file or scripts
<p>i am trying to  run  python file,but really i dont know how to do it?for example let's take following function example</p>

<pre><code>def fib(n):
a, b=0, 1
while a &lt; n:
print(a, end='')
a,b=b,a+b
print()
</code></pre>

<p>it is taken from this  link</p>

<p><a href="http://docs.python.org/py3k/tutorial/controlflow.html" rel="nofollow">http://docs.python.org/py3k/tutorial/controlflow.html</a> 
i  have typed  this code in notepad++ ,but could not understand  several things
1:where is indicated here that function declaration is finished?or which line indicates  that function finished?if we compare  it to c++  we  have</p>

<pre><code>int fibonaci(int n)
{
 return something

}
</code></pre>

<p>second  thing is how can we use for example fibonaci(200)?and last one how can i run?i am also confused  about loops  stopping,but  it is another  topic</p>
