Use NamedTemporaryFile for improved file handling in REPL examples

And uses a `context` object instead of `globals`.

src/sage/repl/load.py

@@ -119,42 +119,44 @@ def load(filename, globals, attach=False):
 
     Note that ``.py`` files are *not* preparsed::
 
-        sage: t = tmp_filename(ext='.py')
-        sage: with open(t, 'w') as f:
-        ....:     _ = f.write("print(('hi', 2^3)); z = -2^7")
-        sage: z = 1
-        sage: sage.repl.load.load(t, globals())
-        ('hi', 1)
-        sage: z
+        sage: from tempfile import NamedTemporaryFile
+        sage: context = { "z": 1}
+        sage: with NamedTemporaryFile(mode='w', suffix='.py') as file:
+        ....:     _ = file.write("print(('hi', 2^3, z)); z = -2^7")
+        ....:     _ = file.seek(0)
+        ....:     sage.repl.load.load(file.name, context)
+        ('hi', 1, 1)
+        sage: context["z"]
         -7
 
     A ``.sage`` file *is* preparsed::
 
-        sage: t = tmp_filename(ext='.sage')
-        sage: with open(t, 'w') as f:
-        ....:     _ = f.write("print(('hi', 2^3)); z = -2^7")
-        sage: z = 1
-        sage: sage.repl.load.load(t, globals())
-        ('hi', 8)
-        sage: z
+        sage: context = { "z": 1, "Integer": Integer }
+        sage: with NamedTemporaryFile(mode='w', suffix='.sage') as file:
+        ....:     _ = file.write("print(('hi', 2^3, z)); z = -2^7")
+        ....:     _ = file.seek(0)
+        ....:     sage.repl.load.load(file.name, context)
+        ('hi', 8, 1)
+        sage: context["z"]
         -128
 
     Cython files are *not* preparsed::
 
-        sage: t = tmp_filename(ext='.pyx')
-        sage: with open(t, 'w') as f:
-        ....:     _ = f.write("print(('hi', 2^3)); z = -2^7")
-        sage: z = 1
-        sage: sage.repl.load.load(t, globals())                                         # needs sage.misc.cython
+        sage: context = { "z": 1 }
+        sage: with NamedTemporaryFile(mode='w', suffix='.pyx') as file:
+        ....:     _ = file.write("print(('hi', 2^3)); z = -2^7")
+        ....:     _ = file.seek(0)
+        ....:     sage.repl.load.load(file.name, context)                                         # needs sage.misc.cython
         Compiling ...
         ('hi', 1)
-        sage: z
+        sage: context["z"]
         -7
 
     If the file is not a Cython, Python, or Sage file, a :exc:`ValueError`
     is raised::
 
-        sage: sage.repl.load.load(tmp_filename(ext='.foo'), globals())
+        sage: with NamedTemporaryFile(mode='w', suffix='.foo') as file:
+        ....:     sage.repl.load.load(file.name, {})
         Traceback (most recent call last):
         ...
         ValueError: unknown file extension '.foo' for load or attach (supported extensions: .py, .pyx, .sage, .spyx, .f, .f90, .m)
@@ -172,12 +174,12 @@ def load(filename, globals, attach=False):
     We attach a file (note that :func:`~sage.repl.attach.attach`
     is equivalent, but available at the global scope by default)::
 
-        sage: t = tmp_filename(ext='.py')
-        sage: with open(t, 'w') as f:
-        ....:     _ = f.write("print('hello world')")
-        sage: sage.repl.load.load(t, globals(), attach=True)
+        sage: with NamedTemporaryFile(mode='w', suffix='.py') as file:
+        ....:     _ = file.write("print('hello world')")
+        ....:     _ = file.seek(0)
+        ....:     sage.repl.load.load(file.name, {}, attach=True)
         hello world
-        sage: t in attached_files()
+        sage: file.name in attached_files()
         True
 
     You cannot attach remote URLs (yet)::