RustPython · youknowone · Jul 25, 2025 · Jul 24, 2025
diff --git a/Lib/pyclbr.py b/Lib/pyclbr.py
@@ -0,0 +1,314 @@
+"""Parse a Python module and describe its classes and functions.
+
+Parse enough of a Python file to recognize imports and class and
+function definitions, and to find out the superclasses of a class.
+
+The interface consists of a single function:
+    readmodule_ex(module, path=None)
+where module is the name of a Python module, and path is an optional
+list of directories where the module is to be searched.  If present,
+path is prepended to the system search path sys.path.  The return value
+is a dictionary.  The keys of the dictionary are the names of the
+classes and functions defined in the module (including classes that are
+defined via the from XXX import YYY construct).  The values are
+instances of classes Class and Function.  One special key/value pair is
+present for packages: the key '__path__' has a list as its value which
+contains the package search path.
+
+Classes and Functions have a common superclass: _Object.  Every instance
+has the following attributes:
+    module  -- name of the module;
+    name    -- name of the object;
+    file    -- file in which the object is defined;
+    lineno  -- line in the file where the object's definition starts;
+    end_lineno -- line in the file where the object's definition ends;
+    parent  -- parent of this object, if any;
+    children -- nested objects contained in this object.
+The 'children' attribute is a dictionary mapping names to objects.
+
+Instances of Function describe functions with the attributes from _Object,
+plus the following:
+    is_async -- if a function is defined with an 'async' prefix
+
+Instances of Class describe classes with the attributes from _Object,
+plus the following:
+    super   -- list of super classes (Class instances if possible);
+    methods -- mapping of method names to beginning line numbers.
+If the name of a super class is not recognized, the corresponding
+entry in the list of super classes is not a class instance but a
+string giving the name of the super class.  Since import statements
+are recognized and imported modules are scanned as well, this
+shouldn't happen often.
+"""
+
+import ast
+import sys
+import importlib.util
+
+__all__ = ["readmodule", "readmodule_ex", "Class", "Function"]
+
+_modules = {}  # Initialize cache of modules we've seen.
+
+
+class _Object:
+    "Information about Python class or function."
+    def __init__(self, module, name, file, lineno, end_lineno, parent):
+        self.module = module
+        self.name = name
+        self.file = file
+        self.lineno = lineno
+        self.end_lineno = end_lineno
+        self.parent = parent
+        self.children = {}
+        if parent is not None:
+            parent.children[name] = self
+
+
+# Odd Function and Class signatures are for back-compatibility.
+class Function(_Object):
+    "Information about a Python function, including methods."
+    def __init__(self, module, name, file, lineno,
+                 parent=None, is_async=False, *, end_lineno=None):
+        super().__init__(module, name, file, lineno, end_lineno, parent)
+        self.is_async = is_async
+        if isinstance(parent, Class):
+            parent.methods[name] = lineno
+
+
+class Class(_Object):
+    "Information about a Python class."
+    def __init__(self, module, name, super_, file, lineno,
+                 parent=None, *, end_lineno=None):
+        super().__init__(module, name, file, lineno, end_lineno, parent)
+        self.super = super_ or []
+        self.methods = {}
+
+
+# These 2 functions are used in these tests
+# Lib/test/test_pyclbr, Lib/idlelib/idle_test/test_browser.py
+def _nest_function(ob, func_name, lineno, end_lineno, is_async=False):
+    "Return a Function after nesting within ob."
+    return Function(ob.module, func_name, ob.file, lineno,
+                    parent=ob, is_async=is_async, end_lineno=end_lineno)
+
+def _nest_class(ob, class_name, lineno, end_lineno, super=None):
+    "Return a Class after nesting within ob."
+    return Class(ob.module, class_name, super, ob.file, lineno,
+                 parent=ob, end_lineno=end_lineno)
+
+
+def readmodule(module, path=None):
+    """Return Class objects for the top-level classes in module.
+
+    This is the original interface, before Functions were added.
+    """
+
+    res = {}
+    for key, value in _readmodule(module, path or []).items():
+        if isinstance(value, Class):
+            res[key] = value
+    return res
+
+def readmodule_ex(module, path=None):
+    """Return a dictionary with all functions and classes in module.
+
+    Search for module in PATH + sys.path.
+    If possible, include imported superclasses.
+    Do this by reading source, without importing (and executing) it.
+    """
+    return _readmodule(module, path or [])
+
+
+def _readmodule(module, path, inpackage=None):
+    """Do the hard work for readmodule[_ex].
+
+    If inpackage is given, it must be the dotted name of the package in
+    which we are searching for a submodule, and then PATH must be the
+    package search path; otherwise, we are searching for a top-level
+    module, and path is combined with sys.path.
+    """
+    # Compute the full module name (prepending inpackage if set).
+    if inpackage is not None:
+        fullmodule = "%s.%s" % (inpackage, module)
+    else:
+        fullmodule = module
+
+    # Check in the cache.
+    if fullmodule in _modules:
+        return _modules[fullmodule]
+
+    # Initialize the dict for this module's contents.
+    tree = {}
+
+    # Check if it is a built-in module; we don't do much for these.
+    if module in sys.builtin_module_names and inpackage is None:
+        _modules[module] = tree
+        return tree
+
+    # Check for a dotted module name.
+    i = module.rfind('.')
+    if i >= 0:
+        package = module[:i]
+        submodule = module[i+1:]
+        parent = _readmodule(package, path, inpackage)
+        if inpackage is not None:
+            package = "%s.%s" % (inpackage, package)
+        if not '__path__' in parent:
+            raise ImportError('No package named {}'.format(package))
+        return _readmodule(submodule, parent['__path__'], package)
+
+    # Search the path for the module.
+    f = None
+    if inpackage is not None:
+        search_path = path
+    else:
+        search_path = path + sys.path
+    spec = importlib.util._find_spec_from_path(fullmodule, search_path)
+    if spec is None:
+        raise ModuleNotFoundError(f"no module named {fullmodule!r}", name=fullmodule)
+    _modules[fullmodule] = tree
+    # Is module a package?
+    if spec.submodule_search_locations is not None:
+        tree['__path__'] = spec.submodule_search_locations
+    try:
+        source = spec.loader.get_source(fullmodule)
+    except (AttributeError, ImportError):
+        # If module is not Python source, we cannot do anything.
+        return tree
+    else:
+        if source is None:
+            return tree
+
+    fname = spec.loader.get_filename(fullmodule)
+    return _create_tree(fullmodule, path, fname, source, tree, inpackage)
+
+
+class _ModuleBrowser(ast.NodeVisitor):
+    def __init__(self, module, path, file, tree, inpackage):
+        self.path = path
+        self.tree = tree
+        self.file = file
+        self.module = module
+        self.inpackage = inpackage
+        self.stack = []
+
+    def visit_ClassDef(self, node):
+        bases = []
+        for base in node.bases:
+            name = ast.unparse(base)
+            if name in self.tree:
+                # We know this super class.
+                bases.append(self.tree[name])
+            elif len(names := name.split(".")) > 1:
+                # Super class form is module.class:
+                # look in module for class.
+                *_, module, class_ = names
+                if module in _modules:
+                    bases.append(_modules[module].get(class_, name))
+            else:
+                bases.append(name)
+
+        parent = self.stack[-1] if self.stack else None
+        class_ = Class(self.module, node.name, bases, self.file, node.lineno,
+                       parent=parent, end_lineno=node.end_lineno)
+        if parent is None:
+            self.tree[node.name] = class_
+        self.stack.append(class_)
+        self.generic_visit(node)
+        self.stack.pop()
+
+    def visit_FunctionDef(self, node, *, is_async=False):
+        parent = self.stack[-1] if self.stack else None
+        function = Function(self.module, node.name, self.file, node.lineno,
+                            parent, is_async, end_lineno=node.end_lineno)
+        if parent is None:
+            self.tree[node.name] = function
+        self.stack.append(function)
+        self.generic_visit(node)
+        self.stack.pop()
+
+    def visit_AsyncFunctionDef(self, node):
+        self.visit_FunctionDef(node, is_async=True)
+
+    def visit_Import(self, node):
+        if node.col_offset != 0:
+            return
+
+        for module in node.names:
+            try:
+                try:
+                    _readmodule(module.name, self.path, self.inpackage)
+                except ImportError:
+                    _readmodule(module.name, [])
+            except (ImportError, SyntaxError):
+                # If we can't find or parse the imported module,
+                # too bad -- don't die here.
+                continue
+
+    def visit_ImportFrom(self, node):
+        if node.col_offset != 0:
+            return
+        try:
+            module = "." * node.level
+            if node.module:
+                module += node.module
+            module = _readmodule(module, self.path, self.inpackage)
+        except (ImportError, SyntaxError):
+            return
+
+        for name in node.names:
+            if name.name in module:
+                self.tree[name.asname or name.name] = module[name.name]
+            elif name.name == "*":
+                for import_name, import_value in module.items():
+                    if import_name.startswith("_"):
+                        continue
+                    self.tree[import_name] = import_value
+
+
+def _create_tree(fullmodule, path, fname, source, tree, inpackage):
+    mbrowser = _ModuleBrowser(fullmodule, path, fname, tree, inpackage)
+    mbrowser.visit(ast.parse(source))
+    return mbrowser.tree
+
+
+def _main():
+    "Print module output (default this file) for quick visual check."
+    import os
+    try:
+        mod = sys.argv[1]
+    except:
+        mod = __file__
+    if os.path.exists(mod):
+        path = [os.path.dirname(mod)]
+        mod = os.path.basename(mod)
+        if mod.lower().endswith(".py"):
+            mod = mod[:-3]
+    else:
+        path = []
+    tree = readmodule_ex(mod, path)
+    lineno_key = lambda a: getattr(a, 'lineno', 0)
+    objs = sorted(tree.values(), key=lineno_key, reverse=True)
+    indent_level = 2
+    while objs:
+        obj = objs.pop()
+        if isinstance(obj, list):
+            # Value is a __path__ key.
+            continue
+        if not hasattr(obj, 'indent'):
+            obj.indent = 0
+
+        if isinstance(obj, _Object):
+            new_objs = sorted(obj.children.values(),
+                              key=lineno_key, reverse=True)
+            for ob in new_objs:
+                ob.indent = obj.indent + indent_level
+            objs.extend(new_objs)
+        if isinstance(obj, Class):
+            print("{}class {} {} {}"
+                  .format(' ' * obj.indent, obj.name, obj.super, obj.lineno))
+        elif isinstance(obj, Function):
+            print("{}def {} {}".format(' ' * obj.indent, obj.name, obj.lineno))
+
+if __name__ == "__main__":
+    _main()