bpo-29446: tkinter 'import *' only imports what it should (GH-14864)

Add __all__ to tkinter.__init__ and submodules.  Replace 'import *'
with explicit imports in some submodules.

Author: Flavian Hautbois

Lib/tkinter/__init__.py

@@ -32,13 +32,13 @@
 
 import enum
 import sys
+import types
 
 import _tkinter # If this fails your Python may not be configured for Tk
 TclError = _tkinter.TclError
 from tkinter.constants import *
 import re
 
-
 wantobjects = 1
 
 TkVersion = float(_tkinter.TK_VERSION)
@@ -4569,5 +4569,9 @@ def _test():
     root.mainloop()
 
 
+__all__ = [name for name, obj in globals().items()
+           if not name.startswith('_') and not isinstance(obj, types.ModuleType)
+           and name not in {'wantobjects'}]
+
 if __name__ == '__main__':
     _test()

Lib/tkinter/colorchooser.py

@@ -21,6 +21,8 @@
 
 from tkinter.commondialog import Dialog
 
+__all__ = ["Chooser", "askcolor"]
+
 
 #
 # color chooser class

Lib/tkinter/commondialog.py

@@ -8,15 +8,17 @@
 # written by Fredrik Lundh, May 1997
 #
 
-from tkinter import *
+__all__ = ["Dialog"]
+
+from tkinter import Frame
 
 
 class Dialog:
 
-    command  = None
+    command = None
 
     def __init__(self, master=None, **options):
-        self.master  = master
+        self.master = master
         self.options = options
         if not master and options.get('parent'):
             self.master = options['parent']

Lib/tkinter/dialog.py

@@ -1,7 +1,8 @@
 # dialog.py -- Tkinter interface to the tk_dialog script.
 
-from tkinter import *
-from tkinter import _cnfmerge
+from tkinter import _cnfmerge, Widget, TclError, Button, Pack
+
+__all__ = ["Dialog"]
 
 DIALOG_ICON = 'questhead'
 

Lib/tkinter/dnd.py

@@ -99,9 +99,10 @@
 
 """
 
-
 import tkinter
 
+__all__ = ["dnd_start", "DndHandler"]
+
 
 # The factory function
 

Lib/tkinter/filedialog.py

@@ -11,14 +11,20 @@
 directory dialogue available in Tk 8.3 and newer.
 These interfaces were written by Fredrik Lundh, May 1997.
 """
+__all__ = ["FileDialog", "LoadFileDialog", "SaveFileDialog",
+           "Open", "SaveAs", "Directory",
+           "askopenfilename", "asksaveasfilename", "askopenfilenames",
+           "askopenfile", "askopenfiles", "asksaveasfile", "askdirectory"]
 
-from tkinter import *
+import fnmatch
+import os
+from tkinter import (
+    Frame, LEFT, YES, BOTTOM, Entry, TOP, Button, Tk, X,
+    Toplevel, RIGHT, Y, END, Listbox, BOTH, Scrollbar,
+)
 from tkinter.dialog import Dialog
 from tkinter import commondialog
 
-import os
-import fnmatch
-
 
 dialogstates = {}
 

Lib/tkinter/font.py

@@ -3,11 +3,12 @@
 # written by Fredrik Lundh, February 1998
 #
 
-__version__ = "0.9"
-
 import itertools
 import tkinter
 
+__version__ = "0.9"
+__all__ = ["NORMAL", "ROMAN", "BOLD", "ITALIC",
+           "nametofont", "Font", "families", "names"]
 
 # weight/slant
 NORMAL = "normal"

Lib/tkinter/messagebox.py

@@ -24,6 +24,10 @@
 
 from tkinter.commondialog import Dialog
 
+__all__ = ["showinfo", "showwarning", "showerror",
+           "askquestion", "askokcancel", "askyesno",
+           "askyesnocancel", "askretrycancel"]
+
 #
 # constants
 

Lib/tkinter/scrolledtext.py

@@ -11,11 +11,11 @@
 Place methods are redirected to the Frame widget however.
 """
 
-__all__ = ['ScrolledText']
-
 from tkinter import Frame, Text, Scrollbar, Pack, Grid, Place
 from tkinter.constants import RIGHT, LEFT, Y, BOTH
 
+__all__ = ['ScrolledText']
+
 
 class ScrolledText(Text):
     def __init__(self, master=None, **kw):

Lib/tkinter/test/test_tkinter/test_misc.py

@@ -7,6 +7,20 @@
 
 class MiscTest(AbstractTkTest, unittest.TestCase):
 
+    def test_all(self):
+        self.assertIn("Widget", tkinter.__all__)
+        # Check that variables from tkinter.constants are also in tkinter.__all__
+        self.assertIn("CASCADE", tkinter.__all__)
+        self.assertIsNotNone(tkinter.CASCADE)
+        # Check that sys, re, and constants are not in tkinter.__all__
+        self.assertNotIn("re", tkinter.__all__)
+        self.assertNotIn("sys", tkinter.__all__)
+        self.assertNotIn("constants", tkinter.__all__)
+        # Check that an underscored functions is not in tkinter.__all__
+        self.assertNotIn("_tkerror", tkinter.__all__)
+        # Check that wantobjects is not in tkinter.__all__
+        self.assertNotIn("wantobjects", tkinter.__all__)
+
     def test_repr(self):
         t = tkinter.Toplevel(self.root, name='top')
         f = tkinter.Frame(t, name='child')