# -*- coding: utf-8 -*- """Tools for inspecting Python objects. Uses syntax highlighting for presenting the various information elements. Similar in spirit to the inspect module, but all calls take a name argument to reference the name under which an object is being read. """ #***************************************************************************** # Copyright (C) 2001-2004 Fernando Perez # # Distributed under the terms of the BSD License. The full license is in # the file COPYING, distributed as part of this software. #***************************************************************************** from __future__ import print_function __all__ = ['Inspector','InspectColors'] # stdlib modules import __builtin__ import inspect import linecache import os import sys import types from collections import namedtuple try: from itertools import izip_longest except ImportError: from itertools import zip_longest as izip_longest # IPython's own from IPython.core import page from IPython.testing.skipdoctest import skip_doctest_py3 from IPython.utils import PyColorize from IPython.utils import io from IPython.utils import openpy from IPython.utils import py3compat from IPython.utils.text import indent from IPython.utils.wildcard import list_namespace from IPython.utils.coloransi import * #**************************************************************************** # Builtin color schemes Colors = TermColors # just a shorthand # Build a few color schemes NoColor = ColorScheme( 'NoColor',{ 'header' : Colors.NoColor, 'normal' : Colors.NoColor # color off (usu. Colors.Normal) } ) LinuxColors = ColorScheme( 'Linux',{ 'header' : Colors.LightRed, 'normal' : Colors.Normal # color off (usu. Colors.Normal) } ) LightBGColors = ColorScheme( 'LightBG',{ 'header' : Colors.Red, 'normal' : Colors.Normal # color off (usu. Colors.Normal) } ) # Build table of color schemes (needed by the parser) InspectColors = ColorSchemeTable([NoColor,LinuxColors,LightBGColors], 'Linux') #**************************************************************************** # Auxiliary functions and objects # See the messaging spec for the definition of all these fields. This list # effectively defines the order of display info_fields = ['type_name', 'base_class', 'string_form', 'namespace', 'length', 'file', 'definition', 'docstring', 'source', 'init_definition', 'class_docstring', 'init_docstring', 'call_def', 'call_docstring', # These won't be printed but will be used to determine how to # format the object 'ismagic', 'isalias', 'isclass', 'argspec', 'found', 'name' ] def object_info(**kw): """Make an object info dict with all fields present.""" infodict = dict(izip_longest(info_fields, [None])) infodict.update(kw) return infodict def getdoc(obj): """Stable wrapper around inspect.getdoc. This can't crash because of attribute problems. It also attempts to call a getdoc() method on the given object. This allows objects which provide their docstrings via non-standard mechanisms (like Pyro proxies) to still be inspected by ipython's ? system.""" # Allow objects to offer customized documentation via a getdoc method: try: ds = obj.getdoc() except Exception: pass else: # if we get extra info, we add it to the normal docstring. if isinstance(ds, basestring): return inspect.cleandoc(ds) try: return inspect.getdoc(obj) except Exception: # Harden against an inspect failure, which can occur with # SWIG-wrapped extensions. return None def getsource(obj,is_binary=False): """Wrapper around inspect.getsource. This can be modified by other projects to provide customized source extraction. Inputs: - obj: an object whose source code we will attempt to extract. Optional inputs: - is_binary: whether the object is known to come from a binary source. This implementation will skip returning any output for binary objects, but custom extractors may know how to meaningfully process them.""" if is_binary: return None else: # get source if obj was decorated with @decorator if hasattr(obj,"__wrapped__"): obj = obj.__wrapped__ try: src = inspect.getsource(obj) except TypeError: if hasattr(obj,'__class__'): src = inspect.getsource(obj.__class__) return src def getargspec(obj): """Get the names and default values of a function's arguments. A tuple of four things is returned: (args, varargs, varkw, defaults). 'args' is a list of the argument names (it may contain nested lists). 'varargs' and 'varkw' are the names of the * and ** arguments or None. 'defaults' is an n-tuple of the default values of the last n arguments. Modified version of inspect.getargspec from the Python Standard Library.""" if inspect.isfunction(obj): func_obj = obj elif inspect.ismethod(obj): func_obj = obj.im_func elif hasattr(obj, '__call__'): func_obj = obj.__call__ else: raise TypeError('arg is not a Python function') args, varargs, varkw = inspect.getargs(func_obj.func_code) return args, varargs, varkw, func_obj.func_defaults def format_argspec(argspec): """Format argspect, convenience wrapper around inspect's. This takes a dict instead of ordered arguments and calls inspect.format_argspec with the arguments in the necessary order. """ return inspect.formatargspec(argspec['args'], argspec['varargs'], argspec['varkw'], argspec['defaults']) def call_tip(oinfo, format_call=True): """Extract call tip data from an oinfo dict. Parameters ---------- oinfo : dict format_call : bool, optional If True, the call line is formatted and returned as a string. If not, a tuple of (name, argspec) is returned. Returns ------- call_info : None, str or (str, dict) tuple. When format_call is True, the whole call information is formattted as a single string. Otherwise, the object's name and its argspec dict are returned. If no call information is available, None is returned. docstring : str or None The most relevant docstring for calling purposes is returned, if available. The priority is: call docstring for callable instances, then constructor docstring for classes, then main object's docstring otherwise (regular functions). """ # Get call definition argspec = oinfo.get('argspec') if argspec is None: call_line = None else: # Callable objects will have 'self' as their first argument, prune # it out if it's there for clarity (since users do *not* pass an # extra first argument explicitly). try: has_self = argspec['args'][0] == 'self' except (KeyError, IndexError): pass else: if has_self: argspec['args'] = argspec['args'][1:] call_line = oinfo['name']+format_argspec(argspec) # Now get docstring. # The priority is: call docstring, constructor docstring, main one. doc = oinfo.get('call_docstring') if doc is None: doc = oinfo.get('init_docstring') if doc is None: doc = oinfo.get('docstring','') return call_line, doc def find_file(obj): """Find the absolute path to the file where an object was defined. This is essentially a robust wrapper around `inspect.getabsfile`. Returns None if no file can be found. Parameters ---------- obj : any Python object Returns ------- fname : str The absolute path to the file where the object was defined. """ # get source if obj was decorated with @decorator if hasattr(obj, '__wrapped__'): obj = obj.__wrapped__ fname = None try: fname = inspect.getabsfile(obj) except TypeError: # For an instance, the file that matters is where its class was # declared. if hasattr(obj, '__class__'): try: fname = inspect.getabsfile(obj.__class__) except TypeError: # Can happen for builtins pass except: pass return fname def find_source_lines(obj): """Find the line number in a file where an object was defined. This is essentially a robust wrapper around `inspect.getsourcelines`. Returns None if no file can be found. Parameters ---------- obj : any Python object Returns ------- lineno : int The line number where the object definition starts. """ # get source if obj was decorated with @decorator if hasattr(obj, '__wrapped__'): obj = obj.__wrapped__ try: try: lineno = inspect.getsourcelines(obj)[1] except TypeError: # For instances, try the class object like getsource() does if hasattr(obj, '__class__'): lineno = inspect.getsourcelines(obj.__class__)[1] except: return None return lineno class Inspector: def __init__(self, color_table=InspectColors, code_color_table=PyColorize.ANSICodeColors, scheme='NoColor', str_detail_level=0): self.color_table = color_table self.parser = PyColorize.Parser(code_color_table,out='str') self.format = self.parser.format self.str_detail_level = str_detail_level self.set_active_scheme(scheme) def _getdef(self,obj,oname=''): """Return the definition header for any callable object. If any exception is generated, None is returned instead and the exception is suppressed.""" try: # We need a plain string here, NOT unicode! hdef = oname + inspect.formatargspec(*getargspec(obj)) return py3compat.unicode_to_str(hdef, 'ascii') except: return None def __head(self,h): """Return a header string with proper colors.""" return '%s%s%s' % (self.color_table.active_colors.header,h, self.color_table.active_colors.normal) def set_active_scheme(self, scheme): self.color_table.set_active_scheme(scheme) self.parser.color_table.set_active_scheme(scheme) def noinfo(self, msg, oname): """Generic message when no information is found.""" print('No %s found' % msg, end=' ') if oname: print('for %s' % oname) else: print() def pdef(self, obj, oname=''): """Print the definition header for any callable object. If the object is a class, print the constructor information.""" if not callable(obj): print('Object is not callable.') return header = '' if inspect.isclass(obj): header = self.__head('Class constructor information:\n') obj = obj.__init__ elif (not py3compat.PY3) and type(obj) is types.InstanceType: obj = obj.__call__ output = self._getdef(obj,oname) if output is None: self.noinfo('definition header',oname) else: print(header,self.format(output), end=' ', file=io.stdout) # In Python 3, all classes are new-style, so they all have __init__. @skip_doctest_py3 def pdoc(self,obj,oname='',formatter = None): """Print the docstring for any object. Optional: -formatter: a function to run the docstring through for specially formatted docstrings. Examples -------- In [1]: class NoInit: ...: pass In [2]: class NoDoc: ...: def __init__(self): ...: pass In [3]: %pdoc NoDoc No documentation found for NoDoc In [4]: %pdoc NoInit No documentation found for NoInit In [5]: obj = NoInit() In [6]: %pdoc obj No documentation found for obj In [5]: obj2 = NoDoc() In [6]: %pdoc obj2 No documentation found for obj2 """ head = self.__head # For convenience lines = [] ds = getdoc(obj) if formatter: ds = formatter(ds) if ds: lines.append(head("Class Docstring:")) lines.append(indent(ds)) if inspect.isclass(obj) and hasattr(obj, '__init__'): init_ds = getdoc(obj.__init__) if init_ds is not None: lines.append(head("Constructor Docstring:")) lines.append(indent(init_ds)) elif hasattr(obj,'__call__'): call_ds = getdoc(obj.__call__) if call_ds: lines.append(head("Calling Docstring:")) lines.append(indent(call_ds)) if not lines: self.noinfo('documentation',oname) else: page.page('\n'.join(lines)) def psource(self,obj,oname=''): """Print the source code for an object.""" # Flush the source cache because inspect can return out-of-date source linecache.checkcache() try: src = getsource(obj) except: self.noinfo('source',oname) else: page.page(self.format(py3compat.unicode_to_str(src))) def pfile(self, obj, oname=''): """Show the whole file where an object was defined.""" lineno = find_source_lines(obj) if lineno is None: self.noinfo('file', oname) return ofile = find_file(obj) # run contents of file through pager starting at line where the object # is defined, as long as the file isn't binary and is actually on the # filesystem. if ofile.endswith(('.so', '.dll', '.pyd')): print('File %r is binary, not printing.' % ofile) elif not os.path.isfile(ofile): print('File %r does not exist, not printing.' % ofile) else: # Print only text files, not extension binaries. Note that # getsourcelines returns lineno with 1-offset and page() uses # 0-offset, so we must adjust. page.page(self.format(openpy.read_py_file(ofile, skip_encoding_cookie=False)), lineno - 1) def _format_fields(self, fields, title_width=12): """Formats a list of fields for display. Parameters ---------- fields : list A list of 2-tuples: (field_title, field_content) title_width : int How many characters to pad titles to. Default 12. """ out = [] header = self.__head for title, content in fields: if len(content.splitlines()) > 1: title = header(title + ":") + "\n" else: title = header((title+":").ljust(title_width)) out.append(title + content) return "\n".join(out) # The fields to be displayed by pinfo: (fancy_name, key_in_info_dict) pinfo_fields1 = [("Type", "type_name"), ] pinfo_fields2 = [("String Form", "string_form"), ] pinfo_fields3 = [("Length", "length"), ("File", "file"), ("Definition", "definition"), ] pinfo_fields_obj = [("Class Docstring", "class_docstring"), ("Constructor Docstring","init_docstring"), ("Call def", "call_def"), ("Call docstring", "call_docstring")] def pinfo(self,obj,oname='',formatter=None,info=None,detail_level=0): """Show detailed information about an object. Optional arguments: - oname: name of the variable pointing to the object. - formatter: special formatter for docstrings (see pdoc) - info: a structure with some information fields which may have been precomputed already. - detail_level: if set to 1, more information is given. """ info = self.info(obj, oname=oname, formatter=formatter, info=info, detail_level=detail_level) displayfields = [] def add_fields(fields): for title, key in fields: field = info[key] if field is not None: displayfields.append((title, field.rstrip())) add_fields(self.pinfo_fields1) # Base class for old-style instances if (not py3compat.PY3) and isinstance(obj, types.InstanceType) and info['base_class']: displayfields.append(("Base Class", info['base_class'].rstrip())) add_fields(self.pinfo_fields2) # Namespace if info['namespace'] != 'Interactive': displayfields.append(("Namespace", info['namespace'].rstrip())) add_fields(self.pinfo_fields3) # Source or docstring, depending on detail level and whether # source found. if detail_level > 0 and info['source'] is not None: displayfields.append(("Source", self.format(py3compat.cast_bytes_py2(info['source'])))) elif info['docstring'] is not None: displayfields.append(("Docstring", info["docstring"])) # Constructor info for classes if info['isclass']: if info['init_definition'] or info['init_docstring']: displayfields.append(("Constructor information", "")) if info['init_definition'] is not None: displayfields.append((" Definition", info['init_definition'].rstrip())) if info['init_docstring'] is not None: displayfields.append((" Docstring", indent(info['init_docstring']))) # Info for objects: else: add_fields(self.pinfo_fields_obj) # Finally send to printer/pager: if displayfields: page.page(self._format_fields(displayfields)) def info(self, obj, oname='', formatter=None, info=None, detail_level=0): """Compute a dict with detailed information about an object. Optional arguments: - oname: name of the variable pointing to the object. - formatter: special formatter for docstrings (see pdoc) - info: a structure with some information fields which may have been precomputed already. - detail_level: if set to 1, more information is given. """ obj_type = type(obj) header = self.__head if info is None: ismagic = 0 isalias = 0 ospace = '' else: ismagic = info.ismagic isalias = info.isalias ospace = info.namespace # Get docstring, special-casing aliases: if isalias: if not callable(obj): try: ds = "Alias to the system command:\n %s" % obj[1] except: ds = "Alias: " + str(obj) else: ds = "Alias to " + str(obj) if obj.__doc__: ds += "\nDocstring:\n" + obj.__doc__ else: ds = getdoc(obj) if ds is None: ds = '' if formatter is not None: ds = formatter(ds) # store output in a dict, we initialize it here and fill it as we go out = dict(name=oname, found=True, isalias=isalias, ismagic=ismagic) string_max = 200 # max size of strings to show (snipped if longer) shalf = int((string_max -5)/2) if ismagic: obj_type_name = 'Magic function' elif isalias: obj_type_name = 'System alias' else: obj_type_name = obj_type.__name__ out['type_name'] = obj_type_name try: bclass = obj.__class__ out['base_class'] = str(bclass) except: pass # String form, but snip if too long in ? form (full in ??) if detail_level >= self.str_detail_level: try: ostr = str(obj) str_head = 'string_form' if not detail_level and len(ostr)>string_max: ostr = ostr[:shalf] + ' <...> ' + ostr[-shalf:] ostr = ("\n" + " " * len(str_head.expandtabs())).\ join(q.strip() for q in ostr.split("\n")) out[str_head] = ostr except: pass if ospace: out['namespace'] = ospace # Length (for strings and lists) try: out['length'] = str(len(obj)) except: pass # Filename where object was defined binary_file = False fname = find_file(obj) if fname is None: # if anything goes wrong, we don't want to show source, so it's as # if the file was binary binary_file = True else: if fname.endswith(('.so', '.dll', '.pyd')): binary_file = True elif fname.endswith(''): fname = 'Dynamically generated function. No source code available.' out['file'] = fname # reconstruct the function definition and print it: defln = self._getdef(obj, oname) if defln: out['definition'] = self.format(defln) # Docstrings only in detail 0 mode, since source contains them (we # avoid repetitions). If source fails, we add them back, see below. if ds and detail_level == 0: out['docstring'] = ds # Original source code for any callable if detail_level: # Flush the source cache because inspect can return out-of-date # source linecache.checkcache() source = None try: try: source = getsource(obj, binary_file) except TypeError: if hasattr(obj, '__class__'): source = getsource(obj.__class__, binary_file) if source is not None: out['source'] = source.rstrip() except Exception: pass if ds and source is None: out['docstring'] = ds # Constructor docstring for classes if inspect.isclass(obj): out['isclass'] = True # reconstruct the function definition and print it: try: obj_init = obj.__init__ except AttributeError: init_def = init_ds = None else: init_def = self._getdef(obj_init,oname) init_ds = getdoc(obj_init) # Skip Python's auto-generated docstrings if init_ds and \ init_ds.startswith('x.__init__(...) initializes'): init_ds = None if init_def or init_ds: if init_def: out['init_definition'] = self.format(init_def) if init_ds: out['init_docstring'] = init_ds # and class docstring for instances: else: # First, check whether the instance docstring is identical to the # class one, and print it separately if they don't coincide. In # most cases they will, but it's nice to print all the info for # objects which use instance-customized docstrings. if ds: try: cls = getattr(obj,'__class__') except: class_ds = None else: class_ds = getdoc(cls) # Skip Python's auto-generated docstrings if class_ds and \ (class_ds.startswith('function(code, globals[,') or \ class_ds.startswith('instancemethod(function, instance,') or \ class_ds.startswith('module(name[,') ): class_ds = None if class_ds and ds != class_ds: out['class_docstring'] = class_ds # Next, try to show constructor docstrings try: init_ds = getdoc(obj.__init__) # Skip Python's auto-generated docstrings if init_ds and \ init_ds.startswith('x.__init__(...) initializes'): init_ds = None except AttributeError: init_ds = None if init_ds: out['init_docstring'] = init_ds # Call form docstring for callable instances if hasattr(obj, '__call__'): call_def = self._getdef(obj.__call__, oname) if call_def is not None: out['call_def'] = self.format(call_def) call_ds = getdoc(obj.__call__) # Skip Python's auto-generated docstrings if call_ds and call_ds.startswith('x.__call__(...) <==> x(...)'): call_ds = None if call_ds: out['call_docstring'] = call_ds # Compute the object's argspec as a callable. The key is to decide # whether to pull it from the object itself, from its __init__ or # from its __call__ method. if inspect.isclass(obj): # Old-style classes need not have an __init__ callable_obj = getattr(obj, "__init__", None) elif callable(obj): callable_obj = obj else: callable_obj = None if callable_obj: try: args, varargs, varkw, defaults = getargspec(callable_obj) except (TypeError, AttributeError): # For extensions/builtins we can't retrieve the argspec pass else: out['argspec'] = dict(args=args, varargs=varargs, varkw=varkw, defaults=defaults) return object_info(**out) def psearch(self,pattern,ns_table,ns_search=[], ignore_case=False,show_all=False): """Search namespaces with wildcards for objects. Arguments: - pattern: string containing shell-like wildcards to use in namespace searches and optionally a type specification to narrow the search to objects of that type. - ns_table: dict of name->namespaces for search. Optional arguments: - ns_search: list of namespace names to include in search. - ignore_case(False): make the search case-insensitive. - show_all(False): show all names, including those starting with underscores. """ #print 'ps pattern:<%r>' % pattern # dbg # defaults type_pattern = 'all' filter = '' cmds = pattern.split() len_cmds = len(cmds) if len_cmds == 1: # Only filter pattern given filter = cmds[0] elif len_cmds == 2: # Both filter and type specified filter,type_pattern = cmds else: raise ValueError('invalid argument string for psearch: <%s>' % pattern) # filter search namespaces for name in ns_search: if name not in ns_table: raise ValueError('invalid namespace <%s>. Valid names: %s' % (name,ns_table.keys())) #print 'type_pattern:',type_pattern # dbg search_result, namespaces_seen = set(), set() for ns_name in ns_search: ns = ns_table[ns_name] # Normally, locals and globals are the same, so we just check one. if id(ns) in namespaces_seen: continue namespaces_seen.add(id(ns)) tmp_res = list_namespace(ns, type_pattern, filter, ignore_case=ignore_case, show_all=show_all) search_result.update(tmp_res) page.page('\n'.join(sorted(search_result)))