import abc import functools import re from StringIO import StringIO from IPython.core.splitinput import LineInfo from IPython.utils import tokenize2 from IPython.utils.openpy import cookie_comment_re from IPython.utils.tokenize2 import generate_tokens, untokenize, TokenError #----------------------------------------------------------------------------- # Globals #----------------------------------------------------------------------------- # The escape sequences that define the syntax transformations IPython will # apply to user input. These can NOT be just changed here: many regular # expressions and other parts of the code may use their hardcoded values, and # for all intents and purposes they constitute the 'IPython syntax', so they # should be considered fixed. ESC_SHELL = '!' # Send line to underlying system shell ESC_SH_CAP = '!!' # Send line to system shell and capture output ESC_HELP = '?' # Find information about object ESC_HELP2 = '??' # Find extra-detailed information about object ESC_MAGIC = '%' # Call magic function ESC_MAGIC2 = '%%' # Call cell-magic function ESC_QUOTE = ',' # Split args on whitespace, quote each as string and call ESC_QUOTE2 = ';' # Quote all args as a single string, call ESC_PAREN = '/' # Call first argument with rest of line as arguments ESC_SEQUENCES = [ESC_SHELL, ESC_SH_CAP, ESC_HELP ,\ ESC_HELP2, ESC_MAGIC, ESC_MAGIC2,\ ESC_QUOTE, ESC_QUOTE2, ESC_PAREN ] class InputTransformer(object): """Abstract base class for line-based input transformers.""" __metaclass__ = abc.ABCMeta @abc.abstractmethod def push(self, line): """Send a line of input to the transformer, returning the transformed input or None if the transformer is waiting for more input. Must be overridden by subclasses. """ pass @abc.abstractmethod def reset(self): """Return, transformed any lines that the transformer has accumulated, and reset its internal state. Must be overridden by subclasses. """ pass @classmethod def wrap(cls, func): """Can be used by subclasses as a decorator, to return a factory that will allow instantiation with the decorated object. """ @functools.wraps(func) def transformer_factory(**kwargs): return cls(func, **kwargs) return transformer_factory class StatelessInputTransformer(InputTransformer): """Wrapper for a stateless input transformer implemented as a function.""" def __init__(self, func): self.func = func def __repr__(self): return "StatelessInputTransformer(func={0!r})".format(self.func) def push(self, line): """Send a line of input to the transformer, returning the transformed input.""" return self.func(line) def reset(self): """No-op - exists for compatibility.""" pass class CoroutineInputTransformer(InputTransformer): """Wrapper for an input transformer implemented as a coroutine.""" def __init__(self, coro, **kwargs): # Prime it self.coro = coro(**kwargs) next(self.coro) def __repr__(self): return "CoroutineInputTransformer(coro={0!r})".format(self.coro) def push(self, line): """Send a line of input to the transformer, returning the transformed input or None if the transformer is waiting for more input. """ return self.coro.send(line) def reset(self): """Return, transformed any lines that the transformer has accumulated, and reset its internal state. """ return self.coro.send(None) class TokenInputTransformer(InputTransformer): """Wrapper for a token-based input transformer. func should accept a list of tokens (5-tuples, see tokenize docs), and return an iterable which can be passed to tokenize.untokenize(). """ def __init__(self, func): self.func = func self.current_line = "" self.line_used = False self.reset_tokenizer() def reset_tokenizer(self): self.tokenizer = generate_tokens(self.get_line) def get_line(self): if self.line_used: raise TokenError self.line_used = True return self.current_line def push(self, line): self.current_line += line + "\n" if self.current_line.isspace(): return self.reset() self.line_used = False tokens = [] stop_at_NL = False try: for intok in self.tokenizer: tokens.append(intok) t = intok[0] if t == tokenize2.NEWLINE or (stop_at_NL and t == tokenize2.NL): # Stop before we try to pull a line we don't have yet break elif t == tokenize2.ERRORTOKEN: stop_at_NL = True except TokenError: # Multi-line statement - stop and try again with the next line self.reset_tokenizer() return None return self.output(tokens) def output(self, tokens): self.current_line = "" self.reset_tokenizer() return untokenize(self.func(tokens)).rstrip('\n') def reset(self): l = self.current_line self.current_line = "" self.reset_tokenizer() if l: return l.rstrip('\n') class assemble_python_lines(TokenInputTransformer): def __init__(self): super(assemble_python_lines, self).__init__(None) def output(self, tokens): return self.reset() @CoroutineInputTransformer.wrap def assemble_logical_lines(): """Join lines following explicit line continuations (\)""" line = '' while True: line = (yield line) if not line or line.isspace(): continue parts = [] while line is not None: if line.endswith('\\') and (not has_comment(line)): parts.append(line[:-1]) line = (yield None) # Get another line else: parts.append(line) break # Output line = ''.join(parts) # Utilities def _make_help_call(target, esc, lspace, next_input=None): """Prepares a pinfo(2)/psearch call from a target name and the escape (i.e. ? or ??)""" method = 'pinfo2' if esc == '??' \ else 'psearch' if '*' in target \ else 'pinfo' arg = " ".join([method, target]) if next_input is None: return '%sget_ipython().magic(%r)' % (lspace, arg) else: return '%sget_ipython().set_next_input(%r);get_ipython().magic(%r)' % \ (lspace, next_input, arg) # These define the transformations for the different escape characters. def _tr_system(line_info): "Translate lines escaped with: !" cmd = line_info.line.lstrip().lstrip(ESC_SHELL) return '%sget_ipython().system(%r)' % (line_info.pre, cmd) def _tr_system2(line_info): "Translate lines escaped with: !!" cmd = line_info.line.lstrip()[2:] return '%sget_ipython().getoutput(%r)' % (line_info.pre, cmd) def _tr_help(line_info): "Translate lines escaped with: ?/??" # A naked help line should just fire the intro help screen if not line_info.line[1:]: return 'get_ipython().show_usage()' return _make_help_call(line_info.ifun, line_info.esc, line_info.pre) def _tr_magic(line_info): "Translate lines escaped with: %" tpl = '%sget_ipython().magic(%r)' if line_info.line.startswith(ESC_MAGIC2): return line_info.line cmd = ' '.join([line_info.ifun, line_info.the_rest]).strip() return tpl % (line_info.pre, cmd) def _tr_quote(line_info): "Translate lines escaped with: ," return '%s%s("%s")' % (line_info.pre, line_info.ifun, '", "'.join(line_info.the_rest.split()) ) def _tr_quote2(line_info): "Translate lines escaped with: ;" return '%s%s("%s")' % (line_info.pre, line_info.ifun, line_info.the_rest) def _tr_paren(line_info): "Translate lines escaped with: /" return '%s%s(%s)' % (line_info.pre, line_info.ifun, ", ".join(line_info.the_rest.split())) tr = { ESC_SHELL : _tr_system, ESC_SH_CAP : _tr_system2, ESC_HELP : _tr_help, ESC_HELP2 : _tr_help, ESC_MAGIC : _tr_magic, ESC_QUOTE : _tr_quote, ESC_QUOTE2 : _tr_quote2, ESC_PAREN : _tr_paren } @StatelessInputTransformer.wrap def escaped_commands(line): """Transform escaped commands - %magic, !system, ?help + various autocalls. """ if not line or line.isspace(): return line lineinf = LineInfo(line) if lineinf.esc not in tr: return line return tr[lineinf.esc](lineinf) _initial_space_re = re.compile(r'\s*') _help_end_re = re.compile(r"""(%{0,2} [a-zA-Z_*][\w*]* # Variable name (\.[a-zA-Z_*][\w*]*)* # .etc.etc ) (\?\??)$ # ? or ?? """, re.VERBOSE) # Extra pseudotokens for multiline strings and data structures _MULTILINE_STRING = object() _MULTILINE_STRUCTURE = object() def _line_tokens(line): """Helper for has_comment and ends_in_comment_or_string.""" readline = StringIO(line).readline toktypes = set() try: for t in generate_tokens(readline): toktypes.add(t[0]) except TokenError as e: # There are only two cases where a TokenError is raised. if 'multi-line string' in e.args[0]: toktypes.add(_MULTILINE_STRING) else: toktypes.add(_MULTILINE_STRUCTURE) return toktypes def has_comment(src): """Indicate whether an input line has (i.e. ends in, or is) a comment. This uses tokenize, so it can distinguish comments from # inside strings. Parameters ---------- src : string A single line input string. Returns ------- comment : bool True if source has a comment. """ return (tokenize2.COMMENT in _line_tokens(src)) def ends_in_comment_or_string(src): """Indicates whether or not an input line ends in a comment or within a multiline string. Parameters ---------- src : string A single line input string. Returns ------- comment : bool True if source ends in a comment or multiline string. """ toktypes = _line_tokens(src) return (tokenize2.COMMENT in toktypes) or (_MULTILINE_STRING in toktypes) @StatelessInputTransformer.wrap def help_end(line): """Translate lines with ?/?? at the end""" m = _help_end_re.search(line) if m is None or ends_in_comment_or_string(line): return line target = m.group(1) esc = m.group(3) lspace = _initial_space_re.match(line).group(0) # If we're mid-command, put it back on the next prompt for the user. next_input = line.rstrip('?') if line.strip() != m.group(0) else None return _make_help_call(target, esc, lspace, next_input) @CoroutineInputTransformer.wrap def cellmagic(end_on_blank_line=False): """Captures & transforms cell magics. After a cell magic is started, this stores up any lines it gets until it is reset (sent None). """ tpl = 'get_ipython().run_cell_magic(%r, %r, %r)' cellmagic_help_re = re.compile('%%\w+\?') line = '' while True: line = (yield line) # consume leading empty lines while not line: line = (yield line) if not line.startswith(ESC_MAGIC2): # This isn't a cell magic, idle waiting for reset then start over while line is not None: line = (yield line) continue if cellmagic_help_re.match(line): # This case will be handled by help_end continue first = line body = [] line = (yield None) while (line is not None) and \ ((line.strip() != '') or not end_on_blank_line): body.append(line) line = (yield None) # Output magic_name, _, first = first.partition(' ') magic_name = magic_name.lstrip(ESC_MAGIC2) line = tpl % (magic_name, first, u'\n'.join(body)) def _strip_prompts(prompt_re, initial_re=None): """Remove matching input prompts from a block of input. Parameters ---------- prompt_re : regular expression A regular expression matching any input prompt (including continuation) initial_re : regular expression, optional A regular expression matching only the initial prompt, but not continuation. If no initial expression is given, prompt_re will be used everywhere. Used mainly for plain Python prompts, where the continuation prompt ``...`` is a valid Python expression in Python 3, so shouldn't be stripped. If initial_re and prompt_re differ, only initial_re will be tested against the first line. If any prompt is found on the first two lines, prompts will be stripped from the rest of the block. """ if initial_re is None: initial_re = prompt_re line = '' while True: line = (yield line) # First line of cell if line is None: continue out, n1 = initial_re.subn('', line, count=1) line = (yield out) if line is None: continue # check for any prompt on the second line of the cell, # because people often copy from just after the first prompt, # so we might not see it in the first line. out, n2 = prompt_re.subn('', line, count=1) line = (yield out) if n1 or n2: # Found a prompt in the first two lines - check for it in # the rest of the cell as well. while line is not None: line = (yield prompt_re.sub('', line, count=1)) else: # Prompts not in input - wait for reset while line is not None: line = (yield line) @CoroutineInputTransformer.wrap def classic_prompt(): """Strip the >>>/... prompts of the Python interactive shell.""" # FIXME: non-capturing version (?:...) usable? prompt_re = re.compile(r'^(>>> ?|\.\.\. ?)') initial_re = re.compile(r'^(>>> ?)') return _strip_prompts(prompt_re, initial_re) @CoroutineInputTransformer.wrap def ipy_prompt(): """Strip IPython's In [1]:/...: prompts.""" # FIXME: non-capturing version (?:...) usable? # FIXME: r'^(In \[\d+\]: | {3}\.{3,}: )' clearer? prompt_re = re.compile(r'^(In \[\d+\]: |\ \ \ \.\.\.+: )') return _strip_prompts(prompt_re) @CoroutineInputTransformer.wrap def leading_indent(): """Remove leading indentation. If the first line starts with a spaces or tabs, the same whitespace will be removed from each following line until it is reset. """ space_re = re.compile(r'^[ \t]+') line = '' while True: line = (yield line) if line is None: continue m = space_re.match(line) if m: space = m.group(0) while line is not None: if line.startswith(space): line = line[len(space):] line = (yield line) else: # No leading spaces - wait for reset while line is not None: line = (yield line) @CoroutineInputTransformer.wrap def strip_encoding_cookie(): """Remove encoding comment if found in first two lines If the first or second line has the `# coding: utf-8` comment, it will be removed. """ line = '' while True: line = (yield line) # check comment on first two lines for i in range(2): if line is None: break if cookie_comment_re.match(line): line = (yield "") else: line = (yield line) # no-op on the rest of the cell while line is not None: line = (yield line) assign_system_re = re.compile(r'(?P(\s*)([\w\.]+)((\s*,\s*[\w\.]+)*))' r'\s*=\s*!\s*(?P.*)') assign_system_template = '%s = get_ipython().getoutput(%r)' @StatelessInputTransformer.wrap def assign_from_system(line): """Transform assignment from system commands (e.g. files = !ls)""" m = assign_system_re.match(line) if m is None: return line return assign_system_template % m.group('lhs', 'cmd') assign_magic_re = re.compile(r'(?P(\s*)([\w\.]+)((\s*,\s*[\w\.]+)*))' r'\s*=\s*%\s*(?P.*)') assign_magic_template = '%s = get_ipython().magic(%r)' @StatelessInputTransformer.wrap def assign_from_magic(line): """Transform assignment from magic commands (e.g. a = %who_ls)""" m = assign_magic_re.match(line) if m is None: return line return assign_magic_template % m.group('lhs', 'cmd')