Example of refactoring using rope library.

tools/telemetry/third_party/rope/rope/base/ast.py

Index: tools/telemetry/third_party/rope/rope/base/ast.py
diff --git a/tools/telemetry/third_party/rope/rope/base/ast.py b/tools/telemetry/third_party/rope/rope/base/ast.py
new file mode 100644
index 0000000000000000000000000000000000000000..d43c83c55bed265f936352df2393c52d059d81d4
--- /dev/null
+++ b/tools/telemetry/third_party/rope/rope/base/ast.py
@@ -0,0 +1,76 @@
+import _ast
+from _ast import *
+
+from rope.base import fscommands
+
+try:
+    unicode
+except NameError:
+    unicode = str
+
+
+def parse(source, filename='<string>'):
+    # NOTE: the raw string should be given to `compile` function
+    if isinstance(source, unicode):
+        source = fscommands.unicode_to_file_data(source)
+    if b'\r' in source:
+        source = source.replace(b'\r\n', b'\n').replace(b'\r', b'\n')
+    if not source.endswith(b'\n'):
+        source += b'\n'
+    try:
+        return compile(source, filename, 'exec', _ast.PyCF_ONLY_AST)
+    except (TypeError, ValueError) as e:
+        error = SyntaxError()
+        error.lineno = 1
+        error.filename = filename
+        error.msg = str(e)
+        raise error
+
+
+def walk(node, walker):
+    """Walk the syntax tree"""
+    method_name = '_' + node.__class__.__name__
+    method = getattr(walker, method_name, None)
+    if method is not None:
+        if isinstance(node, _ast.ImportFrom) and node.module is None:
+            # In python < 2.7 ``node.module == ''`` for relative imports
+            # but for python 2.7 it is None. Generalizing it to ''.
+            node.module = ''
+        return method(node)
+    for child in get_child_nodes(node):
+        walk(child, walker)
+
+
+def get_child_nodes(node):
+    if isinstance(node, _ast.Module):
+        return node.body
+    result = []
+    if node._fields is not None:
+        for name in node._fields:
+            child = getattr(node, name)
+            if isinstance(child, list):
+                for entry in child:
+                    if isinstance(entry, _ast.AST):
+                        result.append(entry)
+            if isinstance(child, _ast.AST):
+                result.append(child)
+    return result
+
+
+def call_for_nodes(node, callback, recursive=False):
+    """If callback returns `True` the child nodes are skipped"""
+    result = callback(node)
+    if recursive and not result:
+        for child in get_child_nodes(node):
+            call_for_nodes(child, callback, recursive)
+
+
+def get_children(node):
+    result = []
+    if node._fields is not None:
+        for name in node._fields:
+            if name in ['lineno', 'col_offset']:
+                continue
+            child = getattr(node, name)
+            result.append(child)
+    return result