def source_code(s, globs, system='sage'):
    r"""
    Format an object's source code to process and display in the
    Sage notebook.

    INPUT:

    - ``s`` - a string; a name of an object

    - ``globs`` - a string:object dictionary; a context in which to
      evaluate ``s``

    - ``system`` - a string (default: 'sage'); the system to which to
      confine the search

    OUTPUT:

    - a string containing the object's file, starting line number, and
      source code

    AUTHORS:

    - William Stein: partly taken from IPython for use in Sage

    - Nick Alexander: extensions
    """
    if system not in ['sage', 'python']:
        s = system + '.' + s

    try:
        obj = eval(s, globs)
    except NameError:
        return html_markup("No object %s"%s)

    try:
        try:
            return html_markup(obj._sage_src_())
        except:
            pass
        newline = "\n\n"  # blank line to start new paragraph
        indent = "    "   # indent source code to mark it as a code block

        filename = sageinspect.sage_getfile(obj)
        try:
            lines, lineno = sageinspect.sage_getsourcelines(obj)
        except IOError as msg:
            return html_markup(str(msg))
        src = indent.join(lines)
        src = indent + format_src(src)
        if not lineno is None:
            output = "**File:** %s"%filename
            output += newline
            output += "**Source Code** (starting at line %s)::"%lineno
            output += newline
            output += src
        return html_markup(output)

    except (TypeError, IndexError):
        return html_markup("Source code for {} is not available.".format(s) +
                           "\nUse {}? to see the documentation.".format(s))

    def _sage_doc_(self):
        """
        Provide documentation for the wrapped function.

        TESTS::

            sage: from sage.misc.sageinspect import sage_getdoc
            sage: from sage.sets.set_from_iterator import Decorator
            sage: d = Decorator()
            sage: d.f = Integer.is_prime
            sage: print sage_getdoc(d)   # indirect doctest
               Test whether "self" is prime.
            ...
               Calls the PARI "isprime" function.
        """
        from sage.misc.sageinspect import sage_getsourcelines, sage_getfile, _extract_embedded_position
        f = self.f
        doc = f.__doc__ or ''
        if _extract_embedded_position(doc) is None:
            try:
                sourcelines = sage_getsourcelines(f)
                from sage.env import SAGE_LIB, SAGE_SRC
                filename = sage_getfile(f)
                # The following is a heuristics to get
                # the file name of the cached function
                # or method
                if filename.startswith(SAGE_SRC):
                    filename = filename[len(SAGE_SRC):]
                elif filename.startswith(SAGE_LIB):
                    filename = filename[len(SAGE_LIB):]
                file_info = "File: %s (starting at line %d)\n"%(filename,sourcelines[1])
                doc = file_info+doc
            except IOError:
                pass
        return doc

def source_code(s, globs, system='sage'):
    r"""
    Format obj's source code for printing in Sage notebook.
    
    AUTHORS:

    - William Stein: partly taken from IPython for use in Sage

    - Nick Alexander: extensions
    """
    if system not in ['sage', 'python']:
        s = system + '.' + s

    try:
        obj = eval(s, globs)
    except NameError:
        return "No object %s"%s
    
    try:
        try:
            return obj._sage_src_()
        except:
            pass
        filename = sageinspect.sage_getfile(obj)
        lines, lineno = sageinspect.sage_getsourcelines(obj, is_binary=False)
        src = ''.join(lines)
        src = sagedoc.format_src(src)
        if not lineno is None:
            src = "File: %s\nSource Code (starting at line %s):\n%s"%(filename, lineno, src)
        return src
    
    except (TypeError, IndexError), msg:
        print msg
        return "Source code for %s not available."%obj

def file_and_line(obj):
    r"""
   Look up source file and line number of obj.

   If the file lies in the Sage library, the path name of the
   corresponding file in the current branch (i.e., the file that gets
   copied into the Sage library upon running 'sage -br').  Note that
   the first line of a file is considered to be 1 rather than 0
   because most editors think that this is the case.
   
   AUTHORS:

   - Nils Bruin (2007-10-03)
   - Simon King (2011-05): Use :mod:`~sage.misc.sageinspect` to get the file
     and the line.
   
   EXAMPLES::

      sage: import sage.misc.edit_module as edit_module
      sage: edit_module.file_and_line(sage)
      ('...sage/__init__.py', 0)

   The following tests against a bug that was fixed in trac ticket #11298::

      sage: edit_module.file_and_line(x)
      ('...sage/symbolic/expression.pyx', ...)

   """
    # d = inspect.getdoc(obj)
    # ret = sage.misc.sageinspect._extract_embedded_position(d);
    # if ret is not None:
    #  (_, filename, lineno) = ret
    # else:
    #  filename = inspect.getsourcefile(obj)
    #  _,lineno = inspect.findsource(obj)

    #
    #  for sage files, the registered source file is the result of the preparsing
    #  these files end in ".py" and have "*autogenerated*" on the second line
    #  for those files, we replace the extension by ".sage" and we subtract
    #  3 from the line number to compensate for the 3 lines that were prefixed
    #  in the preparsing process
    #
    from sage.misc.sageinspect import sage_getfile, sage_getsourcelines

    filename = sage_getfile(obj)
    lineno = sage_getsourcelines(obj)[1] - 1
    if filename.endswith(".py"):
        infile = open(filename, "r")
        infile.readline()
        if infile.readline().find("*autogenerated*") >= 0:
            filename = filename[:-3] + ".sage"
            lineno = lineno - 3

    sageroot = sage.misc.sageinspect.SAGE_ROOT + "/"
    runpathpattern = "^" + sageroot + "local/lib/python[^/]*/site-packages"
    develbranch = sageroot + "devel/sage"
    filename = re.sub(runpathpattern, develbranch, filename)

    return filename, lineno + 1

 def f(wrapper):
     update_wrapper(wrapper, wrapped, assigned=assigned, updated=updated)
     wrapper._sage_src_ = lambda: sage_getsource(wrapped)
     wrapper._sage_src_lines_ = lambda: sage_getsourcelines(wrapped)
     #Getting the signature right in documentation by Sphinx (Trac 9976)
     #The attribute _sage_argspec_() is read by Sphinx if present and used
     #as the argspec of the function instead of using reflection.
     wrapper._sage_argspec_ = lambda: sage_getargspec(wrapped)
     return wrapper

    def _sage_src_lines_(self):
        """
        Returns the source code location for the wrapped function.

        EXAMPLES:
            sage: from sage.misc.sageinspect import sage_getsourcelines
            sage: g = lazy_attribute(banner)
            sage: (src, lines) = sage_getsourcelines(g)
            sage: src[0]
            'def banner():\n'
            sage: lines
            74
        """
        from sage.misc.sageinspect import sage_getsourcelines
        return sage_getsourcelines(self.f)

    def _sage_src_lines_(self):
        """
        Returns the source code location for the wrapped function.

        EXAMPLES::

            sage: from sage.misc.sageinspect import sage_getsourcelines
            sage: g = abstract_method(banner)
            sage: (src, lines) = sage_getsourcelines(g)
            sage: src[0]
            'def banner():\n'
            sage: lines
            81
        """
        from sage.misc.sageinspect import sage_getsourcelines
        return sage_getsourcelines(self._f)

    def _sage_src_lines_(self):
        """
        Returns the source code location for the wrapped function.

        EXAMPLES::

            sage: p = Permutation([1,3,2,4])
            sage: cm = p.left_tableau; cm
            Combinatorial map: Robinson-Schensted insertion tableau
            sage: (src, lines) = cm._sage_src_lines_()
            sage: src[0]
            "    @combinatorial_map(name='Robinson-Schensted insertion tableau')\n"
            sage: lines # random
            2653
        """
        from sage.misc.sageinspect import sage_getsourcelines
        return sage_getsourcelines(self._f)

    def _sage_src_lines_(self):
        r"""
        Returns the list of source lines and the first line number
        of the wrapped function.

        TESTS::

            sage: from sage.misc.sageinspect import sage_getsourcelines
            sage: from sage.sets.set_from_iterator import Decorator
            sage: d = Decorator()
            sage: d.f = MathieuGroup.order
            sage: S = sage_getsourcelines(d)   # indirect doctest
            sage: S[0][2]
            '        Return the number of elements of this group.\n'
            sage: S[0][18]
            '            return Integer(1)\n'
        """
        from sage.misc.sageinspect import sage_getsourcelines
        return sage_getsourcelines(self.f)

    def _sage_doc_(self):
        """
        Provide documentation for the wrapped function.

        TESTS::

            sage: from sage.misc.sageinspect import sage_getdoc
            sage: from sage.sets.set_from_iterator import Decorator
            sage: d = Decorator()
            sage: d.f = Integer.is_prime
            sage: print sage_getdoc(d)   # indirect doctest
               Returns "True" if "self" is prime.
            ...
               IMPLEMENTATION: Calls the PARI "isprime" function.
            <BLANKLINE>
        """
        from sage.misc.sageinspect import sage_getsourcelines, sage_getfile
        f = self.f
        if hasattr(f, "func_doc"):
            try:
                sourcelines = sage_getsourcelines(f)
            except IOError:
                sourcelines = None
            if sourcelines is not None:
                from sage.env import SAGE_LIB, SAGE_SRC
                filename = sage_getfile(f)
                # The following is a heuristics to get
                # the file name of the cached function
                # or method
                if filename.startswith(SAGE_SRC):
                    filename = filename[len(SAGE_SRC):]
                elif filename.startswith(SAGE_LIB):
                    filename = filename[len(SAGE_LIB):]
                file_info = "File: %s (starting at line %d)\n"%(filename,sourcelines[1])
                doc = file_info+(f.func_doc or '')
            else:
                doc = f.func_doc
        else:
            doc = f.__doc__
        return doc

    def _sage_src_lines_(self):
        r"""
        Get the source lines of the dynamic class. This defers to the
        source lines of the ``_doccls`` attribute, which is set when
        the dynamic class is constructed.

        EXAMPLES::

            sage: from sage.misc.sageinspect import sage_getsourcelines
            sage: from sage.structure.dynamic_class import dynamic_class
            sage: C = dynamic_class("SomeClass", [object], doccls=Integer)
            sage: sage_getsourcelines(C)[0][0]
            'cdef class Integer(sage.structure.element.EuclideanDomainElement):\n'
        """
        try:
            # HACK: _doccls is a 1-element tuple to avoid __classget__
            # or trouble with binding behaviour...
            doccls = self._doccls[0]
        except AttributeError:
            raise NotImplementedError("no _doccls found")
        from sage.misc.sageinspect import sage_getsourcelines
        return sage_getsourcelines(doccls)

 def _sage_src_lines():
     return sage_getsourcelines(doccls)