IDLE: fix some RessourceWarning, reuse tokenize.open()

Lib/idlelib/PyShell.py

@@ -201,10 +201,11 @@ class PyShellEditorWindow(EditorWindow):
         breaks = self.breakpoints
         filename = self.io.filename
         try:
-            lines = open(self.breakpointPath,"r").readlines()
+            with open(self.breakpointPath, "r") as fp:
+                lines = fp.readlines()
         except IOError:
             lines = []
-        new_file = open(self.breakpointPath,"w")
+        with open(self.breakpointPath, "w") as new_file:
             for line in lines:
                 if not line.startswith(filename + '='):
                     new_file.write(line)
@@ -212,7 +213,6 @@ class PyShellEditorWindow(EditorWindow):
             breaks = self.breakpoints
             if breaks:
                 new_file.write(filename + '=' + str(breaks) + '\n')
-        new_file.close()
 
     def restore_file_breaks(self):
         self.text.update()   # this enables setting "BREAK" tags to be visible
@@ -220,7 +220,8 @@ class PyShellEditorWindow(EditorWindow):
         if filename is None:
             return
         if os.path.isfile(self.breakpointPath):
-            lines = open(self.breakpointPath,"r").readlines()
+            with open(self.breakpointPath, "r") as fp:
+                lines = fp.readlines()
             for line in lines:
                 if line.startswith(filename + '='):
                     breakpoint_linenumbers = eval(line[len(filename)+1:])
@@ -571,7 +572,8 @@ class ModifiedInterpreter(InteractiveInterpreter):
     def execfile(self, filename, source=None):
         "Execute an existing file"
         if source is None:
-            source = open(filename, "r").read()
+            with open(filename, "r") as fp:
+                source = fp.read()
         try:
             code = compile(source, filename, "exec")
         except (OverflowError, SyntaxError):

Lib/idlelib/ScriptBinding.py

@@ -67,12 +67,7 @@ class ScriptBinding:
 
     def tabnanny(self, filename):
         # XXX: tabnanny should work on binary files as well
-        with open(filename, 'r', encoding='iso-8859-1') as f:
-            two_lines = f.readline() + f.readline()
-        encoding = IOBinding.coding_spec(two_lines)
-        if not encoding:
-            encoding = 'utf-8'
-        f = open(filename, 'r', encoding=encoding)
+        with tokenize.open(filename) as f:
             try:
                 tabnanny.process_tokens(tokenize.generate_tokens(f.readline))
             except tokenize.TokenError as msg: