| """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; |
| 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 copy |
| 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, parent): |
| self.module = module |
| self.name = name |
| self.file = file |
| self.lineno = lineno |
| self.parent = parent |
| self.children = {} |
| if parent is not None: |
| parent.children[name] = self |
| |
| class Function(_Object): |
| "Information about a Python function, including methods." |
| def __init__(self, module, name, file, lineno, parent=None, is_async=False): |
| super().__init__(module, name, file, 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): |
| super().__init__(module, name, file, 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, is_async=False): |
| "Return a Function after nesting within ob." |
| return Function(ob.module, func_name, ob.file, lineno, ob, is_async) |
| |
| def _nest_class(ob, class_name, lineno, super=None): |
| "Return a Class after nesting within ob." |
| return Class(ob.module, class_name, super, ob.file, lineno, ob) |
| |
| 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 |
| ) |
| 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 |
| ) |
| 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() |