Incorporate PEP 8 text from Ian Lee to clarify annotation policy

pep-0008.txt

@@ -514,6 +514,19 @@ Other Recommendations
       def complex(real, imag = 0.0):
           return magic(r = real, i = imag)
 
+- Do use spaces around the ``=`` sign  of an annotated function definition.
+  Additionally, use a single space after the ``:``, as well as a single space
+  on either side of the ``->`` sign representing an annotated return value.
+
+  Yes:  def munge(input: AnyStr):
+  Yes:  def munge(sep: AnyStr = None):
+  Yes:  def munge() -> AnyStr:
+  Yes:  def munge(input: AnyStr, sep: AnyStr = None, limit=1000):
+
+  No:   def munge(input: AnyStr=None):
+  No:   def munge(input:AnyStr):
+  No:   def munge(input: AnyStr)->PosInt:
+
 - Compound statements (multiple statements on the same line) are
   generally discouraged.