[python] How to slice a Pandas Data Frame by position?

I have a Pandas Data Frame object that has 1000 rows and 10 columns. I would simply like to slice the Data Frame and take the first 10 rows. How can I do this? I've been trying to use this:

>>> df.shape
(1000,10)
>>> my_slice = df.ix[10,:]
>>> my_slice.shape
(10,)

Shouldn't my_slice be the first ten rows, ie. a 10 x 10 Data Frame? How can I get the first ten rows, such that my_slice is a 10x10 Data Frame object? Thanks.