import abc import functools import re from StringIO import StringIO from IPython.core.splitinput import LineInfo from IPython.utils import tokenize2 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)' 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) 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. """ readline = StringIO(src).readline toktypes = set() try: for t in generate_tokens(readline): toktypes.add(t[0]) except TokenError: pass return(tokenize2.COMMENT 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 has_comment(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) if (not line) or (not line.startswith(ESC_MAGIC2)): 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): """Remove matching input prompts from a block of input.""" line = '' while True: line = (yield line) # First line of cell if line is None: continue out, n1 = prompt_re.subn('', line, count=1) line = (yield out) # Second line of cell, because people often copy from just after the # first prompt, so we might not see it in the first line. if line is None: continue out, n2 = prompt_re.subn('', line, count=1) line = (yield out) if n1 or n2: # Found the input 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'^(>>> ?|\.\.\. ?)') return _strip_prompts(prompt_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) 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')