Moved an examples from profiling_tutorial.rst to the examples directory.

docs/examples/tutorial/profiling_tutorial/calc_pi_3.pyx

+# cython: profile=True
+
+# calc_pi.pyx
+
+cdef inline double recip_square(int i):
+    return 1. / (i * i)
+
+def approx_pi(int n=10000000):
+    cdef double val = 0.
+    cdef int k
+    for k in range(1, n + 1):
+        val += recip_square(k)
+    return (6 * val) ** .5

docs/src/tutorial/profiling_tutorial.rst

@@ -239,21 +239,9 @@ so it would be wise to turn it into a cdef to reduce call overhead. We should
 also get rid of the power operator: it is turned into a pow(i,2) function call by
 Cython, but we could instead just write i*i which could be faster. The
 whole function is also a good candidate for inlining.  Let's look at the
-necessary changes for these ideas::
+necessary changes for these ideas:
 
-   # encoding: utf-8
-   # cython: profile=True
-   # filename: calc_pi.pyx
-
-   cdef inline double recip_square(int i):
-       return 1./(i*i)
-
-   def approx_pi(int n=10000000):
-       cdef double val = 0.
-       cdef int k
-       for k in xrange(1,n+1):
-           val += recip_square(k)
-       return (6 * val)**.5
+.. literalinclude:: ../../examples/tutorial/profiling_tutorial/calc_pi_3.pyx
 
 Now running the profile script yields: