Pascal's triangle
<p>I am looking for a Pascals triangle using python script</p>

<p>I have done till here and have no idea how to add on</p>

<pre><code>numstr= raw_input("please enter the height:")
height = int( )

tri = []

row1 = [1]
row2 = [1, 1]
tri.append(row1)
tri.append(row2)

while len(tri) &lt; height:
</code></pre>
