bpo-42630: Improve error reporting in Tkinter for absent default root (GH-23781)
* Tkinter functions and constructors which need a default root window
raise now RuntimeError with descriptive message instead of obscure
AttributeError or NameError if it is not created yet or cannot
be created automatically.
* Add tests for all functions which use default root window.
* Fix import in the pynche script.
diff --git a/Lib/tkinter/font.py b/Lib/tkinter/font.py
index a9f79d8..c051162 100644
--- a/Lib/tkinter/font.py
+++ b/Lib/tkinter/font.py
@@ -69,7 +69,7 @@ def _mkdict(self, args):
def __init__(self, root=None, font=None, name=None, exists=False,
**options):
if not root:
- root = tkinter._default_root
+ root = tkinter._get_default_root('use font')
tk = getattr(root, 'tk', root)
if font:
# get actual settings corresponding to the given font
@@ -184,7 +184,7 @@ def metrics(self, *options, **kw):
def families(root=None, displayof=None):
"Get font families (as a tuple)"
if not root:
- root = tkinter._default_root
+ root = tkinter._get_default_root('use font.families()')
args = ()
if displayof:
args = ('-displayof', displayof)
@@ -194,7 +194,7 @@ def families(root=None, displayof=None):
def names(root=None):
"Get names of defined fonts (as a tuple)"
if not root:
- root = tkinter._default_root
+ root = tkinter._get_default_root('use font.names()')
return root.tk.splitlist(root.tk.call("font", "names"))