bpo-45975: Simplify some while-loops with walrus operator (GH-29347)

Lib/wsgiref/handlers.py

@@ -475,10 +475,7 @@ class SimpleHandler(BaseHandler):
         from warnings import warn
         warn("SimpleHandler.stdout.write() should not do partial writes",
             DeprecationWarning)
-        while True:
-            data = data[result:]
-            if not data:
-                break
+        while data := data[result:]:
             result = self.stdout.write(data)
 
     def _flush(self):

Lib/wsgiref/validate.py

@@ -214,10 +214,7 @@ class InputWrapper:
         return lines
 
     def __iter__(self):
-        while 1:
-            line = self.readline()
-            if not line:
-                return
+        while line := self.readline():
             yield line
 
     def close(self):