"""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()