tidy up doctests

sympy/printing/pretty/stringpict.py

@@ -8,10 +8,10 @@
     - minor fixes and changes (mostly to prettyForm)
 
 Updates by Juan Mauricio Matera (email <my last name> at ar_ude_plnu_acisif):
-    - support for align attribute in `left`, `right`, `above` and `bellow`
+    - support for align attribute in `left`, `right`, `above` and `below`
       methods
     - adding the v_align() method
-    - Methods `parens`, `left`, `right`, `above` and `bellow` now returns
+    - Methods `parens`, `left`, `right`, `above` and `below` now returns
       objects of the caller object class.
     - The method `root` now works.
 """
@@ -248,6 +248,8 @@ def below(self, *args, align="c"):
         Examples
         ========
 
+        Let' s consider first how to draw a fraction::
+
         >>> from sympy.printing.pretty.stringpict import stringPict
         >>> print(stringPict("x+3").below(
         ...       stringPict.LINE, '3')) #doctest: +NORMALIZE_WHITESPACE
@@ -257,27 +259,32 @@ def below(self, *args, align="c"):
 
         The optional argument `align` controls the alignment.
         The default value is `'c'`. For `align='l'`,
-        the text is left aligned:
+        the text is left aligned::
 
         >>> print(stringPict("Humpty Dumpty").below(
         ...       stringPict("falls off the wall..."), align="l"))
         Humpty Dumpty
         falls off the wall...
 
-        and for `align='r'`, the elements are right aligned:
+        and for `align='r'`, the elements are right aligned::
+
         >>> print(stringPict("Humpty Dumpty").below(
         ...       stringPict("falls off the wall..."), align="r"))
-               Humpty Dumpty
+                Humpty Dumpty
         falls off the wall...
-
         """
         s, baseline = stringPict.stack(self, *args, align=align)
         return self.__class__(s, self.baseline)
 
     def above(self, *args, align="c"):
-        """Put pictures above this picture.
+        """
+        Put pictures above this picture.
+
         Returns string, baseline arguments for stringPict.
         Baseline is baseline of bottom picture.
+        the horizontal alignment is controlled by the keyword
+        parameter `align`. See stringPict.below() for details and
+        examples.
         """
         string, baseline = stringPict.stack(*(args + (self,)), align=align)
         baseline = len(string.splitlines()) - self.height() + self.baseline
@@ -319,7 +326,8 @@ def leftslash(self):
         return self.left(stringPict(slash, height // 2))
 
     def root(self, n=None):
-        """Produce a nice root symbol.
+        """
+        Produce a nice root symbol.
         Produces ugly results for big n inserts.
 
         >>> from sympy.printing.pretty.stringpict import stringPict, prettyForm
@@ -362,11 +370,10 @@ def root(self, n=None):
         /x+3\\
         |---|         + a
         \\ y /
-
         """
-        # XXX not used anywhere
-        # XXX duplicate of root drawing in pretty.py
-        #put line over expression
+        # TODO: use it in root drawing in PrettyPrinter.
+        # 
+        # put line over expression
         if n is not None:
             if isinstance(n, str):
                 n = stringPict(n)
@@ -476,8 +483,11 @@ def chunks(line):
         return "\n\n".join(pictures)
 
     def subindex(self, sub_index):
-        """
-        Add a `subindex`.
+        """Add a `subindex`.
+
+        Examples
+        ========
+
         >>> from sympy.printing.pretty.stringpict import stringPict
         >>> print( (stringPict("a").below("-").below(stringPict("b"))
         ...         ).parens().subindex(stringPict("a=4")))
@@ -496,13 +506,15 @@ def subsuperindices(self, sub_index, super_index):
         """
         Add  sub and super indices.
 
+        Examples
+        ========
+
         >>> from sympy.printing.pretty.stringpict import stringPict
         >>> print(stringPict("T").subsuperindices(
         ...       stringPict("a"),stringPict("b,c")))
          b,c
         T
          a
-
         """
         width_self = self.width()
         width_index = max(sub_index.width() ,super_index.width())
@@ -518,11 +530,13 @@ def superindex(self, super_index):
         """
         Add a `super index`.
 
+        Examples
+        ========
+
         >>> from sympy.printing.pretty.stringpict import stringPict
         >>> print(stringPict("e").superindex(stringPict("-s(x)")))
             -s(x)
         e
-
         """
         width_self = self.width()
         width_index = super_index.width()