"""Word completion for IPython. This module is a fork of the rlcompleter module in the Python standard library. The original enhancements made to rlcompleter have been sent upstream and were accepted as of Python 2.3, but we need a lot more functionality specific to IPython, so this module will continue to live as an IPython-specific utility. Original rlcompleter documentation: This requires the latest extension to the readline module (the completes keywords, built-ins and globals in __main__; when completing NAME.NAME..., it evaluates (!) the expression up to the last dot and completes its attributes. It's very cool to do "import string" type "string.", hit the completion key (twice), and see the list of names defined by the string module! Tip: to use the tab key as the completion key, call readline.parse_and_bind("tab: complete") Notes: - Exceptions raised by the completer function are *ignored* (and generally cause the completion to fail). This is a feature -- since readline sets the tty device in raw (or cbreak) mode, printing a traceback wouldn't work well without some complicated hoopla to save, reset and restore the tty state. - The evaluation of the NAME.NAME... form may cause arbitrary application defined code to be executed if an object with a __getattr__ hook is found. Since it is the responsibility of the application (or the user) to enable this feature, I consider this an acceptable risk. More complicated expressions (e.g. function calls or indexing operations) are *not* evaluated. - GNU readline is also used by the built-in functions input() and raw_input(), and thus these also benefit/suffer from the completer features. Clearly an interactive application can benefit by specifying its own completer function and using raw_input() for all its input. - When the original stdin is not a tty device, GNU readline is never used, and this module (and the readline module) are silently inactive. """ #***************************************************************************** # # Since this file is essentially a minimally modified copy of the rlcompleter # module which is part of the standard Python distribution, I assume that the # proper procedure is to maintain its copyright as belonging to the Python # Software Foundation (in addition to my own, for all new code). # # Copyright (C) 2008-2011 IPython Development Team # Copyright (C) 2001-2007 Fernando Perez. # Copyright (C) 2001 Python Software Foundation, www.python.org # # 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 #----------------------------------------------------------------------------- # Imports #----------------------------------------------------------------------------- import __builtin__ import __main__ import glob import inspect import itertools import keyword import os import re import shlex import sys from IPython.config.configurable import Configurable from IPython.core.error import TryNext from IPython.core.prefilter import ESC_MAGIC from IPython.utils import generics from IPython.utils import io from IPython.utils.dir2 import dir2 from IPython.utils.process import arg_split from IPython.utils.traitlets import CBool, Enum #----------------------------------------------------------------------------- # Globals #----------------------------------------------------------------------------- # Public API __all__ = ['Completer','IPCompleter'] if sys.platform == 'win32': PROTECTABLES = ' ' else: PROTECTABLES = ' ()[]{}?=\\|;:\'#*"^&' #----------------------------------------------------------------------------- # Main functions and classes #----------------------------------------------------------------------------- def has_open_quotes(s): """Return whether a string has open quotes. This simply counts whether the number of quote characters of either type in the string is odd. Returns ------- If there is an open quote, the quote character is returned. Else, return False. """ # We check " first, then ', so complex cases with nested quotes will get # the " to take precedence. if s.count('"') % 2: return '"' elif s.count("'") % 2: return "'" else: return False def protect_filename(s): """Escape a string to protect certain characters.""" return "".join([(ch in PROTECTABLES and '\\' + ch or ch) for ch in s]) def mark_dirs(matches): """Mark directories in input list by appending '/' to their names.""" out = [] isdir = os.path.isdir for x in matches: if isdir(x): out.append(x+'/') else: out.append(x) return out def expand_user(path): """Expand '~'-style usernames in strings. This is similar to :func:`os.path.expanduser`, but it computes and returns extra information that will be useful if the input was being used in computing completions, and you wish to return the completions with the original '~' instead of its expanded value. Parameters ---------- path : str String to be expanded. If no ~ is present, the output is the same as the input. Returns ------- newpath : str Result of ~ expansion in the input path. tilde_expand : bool Whether any expansion was performed or not. tilde_val : str The value that ~ was replaced with. """ # Default values tilde_expand = False tilde_val = '' newpath = path if path.startswith('~'): tilde_expand = True rest = len(path)-1 newpath = os.path.expanduser(path) if rest: tilde_val = newpath[:-rest] else: tilde_val = newpath return newpath, tilde_expand, tilde_val def compress_user(path, tilde_expand, tilde_val): """Does the opposite of expand_user, with its outputs. """ if tilde_expand: return path.replace(tilde_val, '~') else: return path def single_dir_expand(matches): "Recursively expand match lists containing a single dir." if len(matches) == 1 and os.path.isdir(matches[0]): # Takes care of links to directories also. Use '/' # explicitly, even under Windows, so that name completions # don't end up escaped. d = matches[0] if d[-1] in ['/','\\']: d = d[:-1] subdirs = os.listdir(d) if subdirs: matches = [ (d + '/' + p) for p in subdirs] return single_dir_expand(matches) else: return matches else: return matches class Bunch(object): pass DELIMS = ' \t\n`!@#$^&*()=+[{]}\\|;:\'",<>?' GREEDY_DELIMS = ' \r\n' class CompletionSplitter(object): """An object to split an input line in a manner similar to readline. By having our own implementation, we can expose readline-like completion in a uniform manner to all frontends. This object only needs to be given the line of text to be split and the cursor position on said line, and it returns the 'word' to be completed on at the cursor after splitting the entire line. What characters are used as splitting delimiters can be controlled by setting the `delims` attribute (this is a property that internally automatically builds the necessary """ # Private interface # A string of delimiter characters. The default value makes sense for # IPython's most typical usage patterns. _delims = DELIMS # The expression (a normal string) to be compiled into a regular expression # for actual splitting. We store it as an attribute mostly for ease of # debugging, since this type of code can be so tricky to debug. _delim_expr = None # The regular expression that does the actual splitting _delim_re = None def __init__(self, delims=None): delims = CompletionSplitter._delims if delims is None else delims self.set_delims(delims) def set_delims(self, delims): """Set the delimiters for line splitting.""" expr = '[' + ''.join('\\'+ c for c in delims) + ']' self._delim_re = re.compile(expr) self._delims = delims self._delim_expr = expr def get_delims(self): """Return the string of delimiter characters.""" return self._delims def split_line(self, line, cursor_pos=None): """Split a line of text with a cursor at the given position. """ l = line if cursor_pos is None else line[:cursor_pos] return self._delim_re.split(l)[-1] class Completer(Configurable): greedy = CBool(False, config=True, help="""Activate greedy completion This will enable completion on elements of lists, results of function calls, etc., but can be unsafe because the code is actually evaluated on TAB. """ ) def __init__(self, namespace=None, global_namespace=None, config=None, **kwargs): """Create a new completer for the command line. Completer(namespace=ns,global_namespace=ns2) -> completer instance. If unspecified, the default namespace where completions are performed is __main__ (technically, __main__.__dict__). Namespaces should be given as dictionaries. An optional second namespace can be given. This allows the completer to handle cases where both the local and global scopes need to be distinguished. Completer instances should be used as the completion mechanism of readline via the set_completer() call: readline.set_completer(Completer(my_namespace).complete) """ # Don't bind to namespace quite yet, but flag whether the user wants a # specific namespace or to use __main__.__dict__. This will allow us # to bind to __main__.__dict__ at completion time, not now. if namespace is None: self.use_main_ns = 1 else: self.use_main_ns = 0 self.namespace = namespace # The global namespace, if given, can be bound directly if global_namespace is None: self.global_namespace = {} else: self.global_namespace = global_namespace super(Completer, self).__init__(config=config, **kwargs) def complete(self, text, state): """Return the next possible completion for 'text'. This is called successively with state == 0, 1, 2, ... until it returns None. The completion should begin with 'text'. """ if self.use_main_ns: self.namespace = __main__.__dict__ if state == 0: if "." in text: self.matches = self.attr_matches(text) else: self.matches = self.global_matches(text) try: return self.matches[state] except IndexError: return None def global_matches(self, text): """Compute matches when text is a simple name. Return a list of all keywords, built-in functions and names currently defined in self.namespace or self.global_namespace that match. """ #print 'Completer->global_matches, txt=%r' % text # dbg matches = [] match_append = matches.append n = len(text) for lst in [keyword.kwlist, __builtin__.__dict__.keys(), self.namespace.keys(), self.global_namespace.keys()]: for word in lst: if word[:n] == text and word != "__builtins__": match_append(word) return matches def attr_matches(self, text): """Compute matches when text contains a dot. Assuming the text is of the form NAME.NAME....[NAME], and is evaluatable in self.namespace or self.global_namespace, it will be evaluated and its attributes (as revealed by dir()) are used as possible completions. (For class instances, class members are are also considered.) WARNING: this can still invoke arbitrary C code, if an object with a __getattr__ hook is evaluated. """ #io.rprint('Completer->attr_matches, txt=%r' % text) # dbg # Another option, seems to work great. Catches things like ''. m = re.match(r"(\S+(\.\w+)*)\.(\w*)$", text) if m: expr, attr = m.group(1, 3) elif self.greedy: m2 = re.match(r"(.+)\.(\w*)$", self.line_buffer) if not m2: return [] expr, attr = m2.group(1,2) else: return [] try: obj = eval(expr, self.namespace) except: try: obj = eval(expr, self.global_namespace) except: return [] words = dir2(obj) try: words = generics.complete_object(obj, words) except TryNext: pass except Exception: # Silence errors from completion function #raise # dbg pass # Build match list to return n = len(attr) res = ["%s.%s" % (expr, w) for w in words if w[:n] == attr ] return res class IPCompleter(Completer): """Extension of the completer class with IPython-specific features""" def _greedy_changed(self, name, old, new): """update the splitter and readline delims when greedy is changed""" if new: self.splitter.set_delims(GREEDY_DELIMS) else: self.splitter.set_delims(DELIMS) if self.readline: self.readline.set_completer_delims(self.splitter.get_delims()) merge_completions = CBool(True, config=True, help="""Whether to merge completion results into a single list If False, only the completion results from the first non-empty completer will be returned. """ ) omit__names = Enum((0,1,2), default_value=2, config=True, help="""Instruct the completer to omit private method names Specifically, when completing on ``object.``. When 2 [default]: all names that start with '_' will be excluded. When 1: all 'magic' names (``__foo__``) will be excluded. When 0: nothing will be excluded. """ ) def __init__(self, shell=None, namespace=None, global_namespace=None, alias_table=None, use_readline=True, config=None, **kwargs): """IPCompleter() -> completer Return a completer object suitable for use by the readline library via readline.set_completer(). Inputs: - shell: a pointer to the ipython shell itself. This is needed because this completer knows about magic functions, and those can only be accessed via the ipython instance. - namespace: an optional dict where completions are performed. - global_namespace: secondary optional dict for completions, to handle cases (such as IPython embedded inside functions) where both Python scopes are visible. - If alias_table is supplied, it should be a dictionary of aliases to complete. use_readline : bool, optional If true, use the readline library. This completer can still function without readline, though in that case callers must provide some extra information on each call about the current line.""" self.magic_escape = ESC_MAGIC self.splitter = CompletionSplitter() # Readline configuration, only used by the rlcompleter method. if use_readline: # We store the right version of readline so that later code import IPython.utils.rlineimpl as readline self.readline = readline else: self.readline = None # _greedy_changed() depends on splitter and readline being defined: Completer.__init__(self, namespace=namespace, global_namespace=global_namespace, config=config, **kwargs) # List where completion matches will be stored self.matches = [] self.shell = shell.shell if alias_table is None: alias_table = {} self.alias_table = alias_table # Regexp to split filenames with spaces in them self.space_name_re = re.compile(r'([^\\] )') # Hold a local ref. to glob.glob for speed self.glob = glob.glob # Determine if we are running on 'dumb' terminals, like (X)Emacs # buffers, to avoid completion problems. term = os.environ.get('TERM','xterm') self.dumb_terminal = term in ['dumb','emacs'] # Special handling of backslashes needed in win32 platforms if sys.platform == "win32": self.clean_glob = self._clean_glob_win32 else: self.clean_glob = self._clean_glob # All active matcher routines for completion self.matchers = [self.python_matches, self.file_matches, self.magic_matches, self.alias_matches, self.python_func_kw_matches, ] def all_completions(self, text): """ Wrapper around the complete method for the benefit of emacs and pydb. """ return self.complete(text)[1] def _clean_glob(self,text): return self.glob("%s*" % text) def _clean_glob_win32(self,text): return [f.replace("\\","/") for f in self.glob("%s*" % text)] def file_matches(self, text): """Match filenames, expanding ~USER type strings. Most of the seemingly convoluted logic in this completer is an attempt to handle filenames with spaces in them. And yet it's not quite perfect, because Python's readline doesn't expose all of the GNU readline details needed for this to be done correctly. For a filename with a space in it, the printed completions will be only the parts after what's already been typed (instead of the full completions, as is normally done). I don't think with the current (as of Python 2.3) Python readline it's possible to do better.""" #io.rprint('Completer->file_matches: <%r>' % text) # dbg # chars that require escaping with backslash - i.e. chars # that readline treats incorrectly as delimiters, but we # don't want to treat as delimiters in filename matching # when escaped with backslash if text.startswith('!'): text = text[1:] text_prefix = '!' else: text_prefix = '' text_until_cursor = self.text_until_cursor # track strings with open quotes open_quotes = has_open_quotes(text_until_cursor) if '(' in text_until_cursor or '[' in text_until_cursor: lsplit = text else: try: # arg_split ~ shlex.split, but with unicode bugs fixed by us lsplit = arg_split(text_until_cursor)[-1] except ValueError: # typically an unmatched ", or backslash without escaped char. if open_quotes: lsplit = text_until_cursor.split(open_quotes)[-1] else: return [] except IndexError: # tab pressed on empty line lsplit = "" if not open_quotes and lsplit != protect_filename(lsplit): # if protectables are found, do matching on the whole escaped name has_protectables = True text0,text = text,lsplit else: has_protectables = False text = os.path.expanduser(text) if text == "": return [text_prefix + protect_filename(f) for f in self.glob("*")] # Compute the matches from the filesystem m0 = self.clean_glob(text.replace('\\','')) if has_protectables: # If we had protectables, we need to revert our changes to the # beginning of filename so that we don't double-write the part # of the filename we have so far len_lsplit = len(lsplit) matches = [text_prefix + text0 + protect_filename(f[len_lsplit:]) for f in m0] else: if open_quotes: # if we have a string with an open quote, we don't need to # protect the names at all (and we _shouldn't_, as it # would cause bugs when the filesystem call is made). matches = m0 else: matches = [text_prefix + protect_filename(f) for f in m0] #io.rprint('mm', matches) # dbg return mark_dirs(matches) def magic_matches(self, text): """Match magics""" #print 'Completer->magic_matches:',text,'lb',self.text_until_cursor # dbg # Get all shell magics now rather than statically, so magics loaded at # runtime show up too magics = self.shell.lsmagic() pre = self.magic_escape baretext = text.lstrip(pre) return [ pre+m for m in magics if m.startswith(baretext)] def alias_matches(self, text): """Match internal system aliases""" #print 'Completer->alias_matches:',text,'lb',self.text_until_cursor # dbg # if we are not in the first 'item', alias matching # doesn't make sense - unless we are starting with 'sudo' command. main_text = self.text_until_cursor.lstrip() if ' ' in main_text and not main_text.startswith('sudo'): return [] text = os.path.expanduser(text) aliases = self.alias_table.keys() if text == '': return aliases else: return [a for a in aliases if a.startswith(text)] def python_matches(self,text): """Match attributes or global python names""" #io.rprint('Completer->python_matches, txt=%r' % text) # dbg if "." in text: try: matches = self.attr_matches(text) if text.endswith('.') and self.omit__names: if self.omit__names == 1: # true if txt is _not_ a __ name, false otherwise: no__name = (lambda txt: re.match(r'.*\.__.*?__',txt) is None) else: # true if txt is _not_ a _ name, false otherwise: no__name = (lambda txt: re.match(r'.*\._.*?',txt) is None) matches = filter(no__name, matches) except NameError: # catches . matches = [] else: matches = self.global_matches(text) return matches def _default_arguments(self, obj): """Return the list of default arguments of obj if it is callable, or empty list otherwise.""" if not (inspect.isfunction(obj) or inspect.ismethod(obj)): # for classes, check for __init__,__new__ if inspect.isclass(obj): obj = (getattr(obj,'__init__',None) or getattr(obj,'__new__',None)) # for all others, check if they are __call__able elif hasattr(obj, '__call__'): obj = obj.__call__ # XXX: is there a way to handle the builtins ? try: args,_,_1,defaults = inspect.getargspec(obj) if defaults: return args[-len(defaults):] except TypeError: pass return [] def python_func_kw_matches(self,text): """Match named parameters (kwargs) of the last open function""" if "." in text: # a parameter cannot be dotted return [] try: regexp = self.__funcParamsRegex except AttributeError: regexp = self.__funcParamsRegex = re.compile(r''' '.*?' | # single quoted strings or ".*?" | # double quoted strings or \w+ | # identifier \S # other characters ''', re.VERBOSE | re.DOTALL) # 1. find the nearest identifier that comes before an unclosed # parenthesis e.g. for "foo (1+bar(x), pa", the candidate is "foo" tokens = regexp.findall(self.line_buffer) tokens.reverse() iterTokens = iter(tokens); openPar = 0 for token in iterTokens: if token == ')': openPar -= 1 elif token == '(': openPar += 1 if openPar > 0: # found the last unclosed parenthesis break else: return [] # 2. Concatenate dotted names ("foo.bar" for "foo.bar(x, pa" ) ids = [] isId = re.compile(r'\w+$').match while True: try: ids.append(iterTokens.next()) if not isId(ids[-1]): ids.pop(); break if not iterTokens.next() == '.': break except StopIteration: break # lookup the candidate callable matches either using global_matches # or attr_matches for dotted names if len(ids) == 1: callableMatches = self.global_matches(ids[0]) else: callableMatches = self.attr_matches('.'.join(ids[::-1])) argMatches = [] for callableMatch in callableMatches: try: namedArgs = self._default_arguments(eval(callableMatch, self.namespace)) except: continue for namedArg in namedArgs: if namedArg.startswith(text): argMatches.append("%s=" %namedArg) return argMatches def dispatch_custom_completer(self, text): #io.rprint("Custom! '%s' %s" % (text, self.custom_completers)) # dbg line = self.line_buffer if not line.strip(): return None # Create a little structure to pass all the relevant information about # the current completion to any custom completer. event = Bunch() event.line = line event.symbol = text cmd = line.split(None,1)[0] event.command = cmd event.text_until_cursor = self.text_until_cursor #print "\ncustom:{%s]\n" % event # dbg # for foo etc, try also to find completer for %foo if not cmd.startswith(self.magic_escape): try_magic = self.custom_completers.s_matches( self.magic_escape + cmd) else: try_magic = [] for c in itertools.chain(self.custom_completers.s_matches(cmd), try_magic, self.custom_completers.flat_matches(self.text_until_cursor)): #print "try",c # dbg try: res = c(event) if res: # first, try case sensitive match withcase = [r for r in res if r.startswith(text)] if withcase: return withcase # if none, then case insensitive ones are ok too text_low = text.lower() return [r for r in res if r.lower().startswith(text_low)] except TryNext: pass return None def complete(self, text=None, line_buffer=None, cursor_pos=None): """Find completions for the given text and line context. This is called successively with state == 0, 1, 2, ... until it returns None. The completion should begin with 'text'. Note that both the text and the line_buffer are optional, but at least one of them must be given. Parameters ---------- text : string, optional Text to perform the completion on. If not given, the line buffer is split using the instance's CompletionSplitter object. line_buffer : string, optional If not given, the completer attempts to obtain the current line buffer via readline. This keyword allows clients which are requesting for text completions in non-readline contexts to inform the completer of the entire text. cursor_pos : int, optional Index of the cursor in the full line buffer. Should be provided by remote frontends where kernel has no access to frontend state. Returns ------- text : str Text that was actually used in the completion. matches : list A list of completion matches. """ #io.rprint('\nCOMP1 %r %r %r' % (text, line_buffer, cursor_pos)) # dbg # if the cursor position isn't given, the only sane assumption we can # make is that it's at the end of the line (the common case) if cursor_pos is None: cursor_pos = len(line_buffer) if text is None else len(text) # if text is either None or an empty string, rely on the line buffer if not text: text = self.splitter.split_line(line_buffer, cursor_pos) # If no line buffer is given, assume the input text is all there was if line_buffer is None: line_buffer = text self.line_buffer = line_buffer self.text_until_cursor = self.line_buffer[:cursor_pos] #io.rprint('\nCOMP2 %r %r %r' % (text, line_buffer, cursor_pos)) # dbg # Start with a clean slate of completions self.matches[:] = [] custom_res = self.dispatch_custom_completer(text) if custom_res is not None: # did custom completers produce something? self.matches = custom_res else: # Extend the list of completions with the results of each # matcher, so we return results to the user from all # namespaces. if self.merge_completions: self.matches = [] for matcher in self.matchers: try: self.matches.extend(matcher(text)) except: # Show the ugly traceback if the matcher causes an # exception, but do NOT crash the kernel! sys.excepthook(*sys.exc_info()) else: for matcher in self.matchers: self.matches = matcher(text) if self.matches: break # FIXME: we should extend our api to return a dict with completions for # different types of objects. The rlcomplete() method could then # simply collapse the dict into a list for readline, but we'd have # richer completion semantics in other evironments. self.matches = sorted(set(self.matches)) #io.rprint('COMP TEXT, MATCHES: %r, %r' % (text, self.matches)) # dbg return text, self.matches def rlcomplete(self, text, state): """Return the state-th possible completion for 'text'. This is called successively with state == 0, 1, 2, ... until it returns None. The completion should begin with 'text'. Parameters ---------- text : string Text to perform the completion on. state : int Counter used by readline. """ if state==0: self.line_buffer = line_buffer = self.readline.get_line_buffer() cursor_pos = self.readline.get_endidx() #io.rprint("\nRLCOMPLETE: %r %r %r" % # (text, line_buffer, cursor_pos) ) # dbg # if there is only a tab on a line with only whitespace, instead of # the mostly useless 'do you want to see all million completions' # message, just do the right thing and give the user his tab! # Incidentally, this enables pasting of tabbed text from an editor # (as long as autoindent is off). # It should be noted that at least pyreadline still shows file # completions - is there a way around it? # don't apply this on 'dumb' terminals, such as emacs buffers, so # we don't interfere with their own tab-completion mechanism. if not (self.dumb_terminal or line_buffer.strip()): self.readline.insert_text('\t') sys.stdout.flush() return None # Note: debugging exceptions that may occur in completion is very # tricky, because readline unconditionally silences them. So if # during development you suspect a bug in the completion code, turn # this flag on temporarily by uncommenting the second form (don't # flip the value in the first line, as the '# dbg' marker can be # automatically detected and is used elsewhere). DEBUG = False #DEBUG = True # dbg if DEBUG: try: self.complete(text, line_buffer, cursor_pos) except: import traceback; traceback.print_exc() else: # The normal production version is here # This method computes the self.matches array self.complete(text, line_buffer, cursor_pos) try: return self.matches[state] except IndexError: return None