gh-107424: avoid using lambda functions in textwrap.indent()

Lib/textwrap.py

@@ -475,18 +475,22 @@ def indent(text, prefix, predicate=None):
     it will default to adding 'prefix' to all non-empty lines that do not
     consist solely of whitespace characters.
     """
+    prefixed_lines = []
+
     if predicate is None:
         # str.splitlines(True) doesn't produce empty string.
         #  ''.splitlines(True) => []
         #  'foo\n'.splitlines(True) => ['foo\n']
-        # So we can use just `not s.isspace()` here.
-        predicate = lambda s: not s.isspace()
-
-    prefixed_lines = []
-    for line in text.splitlines(True):
-        if predicate(line):
-            prefixed_lines.append(prefix)
-        prefixed_lines.append(line)
+        # So we can use just `not line.isspace()` here.
+        for line in text.splitlines(True):
+            if not line.isspace():
+                prefixed_lines.append(prefix)
+            prefixed_lines.append(line)
+    else:
+        for line in text.splitlines(True):
+            if predicate(line):
+                prefixed_lines.append(prefix)
+            prefixed_lines.append(line)
 
     return ''.join(prefixed_lines)