[docs] code bug in doc

[rainbowsally]

In section "4.6. Defining Functions" on this page,

https://docs.python.org/2.7/tutorial/controlflow.html

The code doesn't end with a newline and produces a syntax error due to 
the >>> prompt at the end of the output.

Add another 'print' at the end to correct it.

>>>def  fib(n):     # write Fibonacci series up to n
...      """Print a Fibonacci series up to n."""
...      a,  b  =  0,  1
...      while  a  <  n:
...          print  a,
...          a,  b  =  b,  a+b ... print ''

or something like that.

May also need a note to describe what the comma is doing in the "print 
a" line. This comma isn't mentioned again until the Input and Output docs in
https://docs.python.org/2.7/tutorial/inputoutput.html

>>>for  x  in  range(1,  11):
...      print  repr(x).rjust(2),  repr(x*x).rjust(3),
...      # Note trailing comma on previous line
...      print  repr(x*x*x).rjust(4)

But the function of the trailing comma is not explained there either.

Been holding off of learning a new programming language for quite a 
while but I may just take the leap with Python this time.