#+BEGIN_SRC python
  1 + 1
#+END_SRC

A markdown cell
And below, the cell for function f has non trivial cell metadata. And the next cell as well.

#+BEGIN_SRC python
  def f(x):
      return x
#+END_SRC

#+BEGIN_SRC python
  f(5)
#+END_SRC

More text

#+BEGIN_SRC python
  2 + 2
#+END_SRC
