"""Patched version of standard library tokenize, to deal with various bugs. Based on Python 3.2 code. Patches: - Gareth Rees' patch for Python issue #12691 (untokenizing) - Except we don't encode the output of untokenize - Python 2 compatible syntax, so that it can be byte-compiled at installation - Newlines in comments and blank lines should be either NL or NEWLINE, depending on whether they are in a multi-line statement. Filed as Python issue #17061. - Export generate_tokens & TokenError - u and rb literals are allowed under Python 3.3 and above. ------------------------------------------------------------------------------ Tokenization help for Python programs. tokenize(readline) is a generator that breaks a stream of bytes into Python tokens. It decodes the bytes according to PEP-0263 for determining source file encoding. It accepts a readline-like method which is called repeatedly to get the next line of input (or b"" for EOF). It generates 5-tuples with these members: the token type (see token.py) the token (a string) the starting (row, column) indices of the token (a 2-tuple of ints) the ending (row, column) indices of the token (a 2-tuple of ints) the original line (string) It is designed to match the working of the Python tokenizer exactly, except that it produces COMMENT tokens for comments and gives type OP for all operators. Additionally, all token lists start with an ENCODING token which tells you which encoding was used to decode the bytes stream. """ from __future__ import absolute_import __author__ = 'Ka-Ping Yee ' __credits__ = ('GvR, ESR, Tim Peters, Thomas Wouters, Fred Drake, ' 'Skip Montanaro, Raymond Hettinger, Trent Nelson, ' 'Michael Foord') import builtins import re import sys from token import * from codecs import lookup, BOM_UTF8 import collections from io import TextIOWrapper cookie_re = re.compile("coding[:=]\s*([-\w.]+)") import token __all__ = token.__all__ + ["COMMENT", "tokenize", "detect_encoding", "NL", "untokenize", "ENCODING", "TokenInfo"] del token __all__ += ["generate_tokens", "TokenError"] COMMENT = N_TOKENS tok_name[COMMENT] = 'COMMENT' NL = N_TOKENS + 1 tok_name[NL] = 'NL' ENCODING = N_TOKENS + 2 tok_name[ENCODING] = 'ENCODING' N_TOKENS += 3 class TokenInfo(collections.namedtuple('TokenInfo', 'type string start end line')): def __repr__(self): annotated_type = '%d (%s)' % (self.type, tok_name[self.type]) return ('TokenInfo(type=%s, string=%r, start=%r, end=%r, line=%r)' % self._replace(type=annotated_type)) def group(*choices): return '(' + '|'.join(choices) + ')' def any(*choices): return group(*choices) + '*' def maybe(*choices): return group(*choices) + '?' # Note: we use unicode matching for names ("\w") but ascii matching for # number literals. Whitespace = r'[ \f\t]*' Comment = r'#[^\r\n]*' Ignore = Whitespace + any(r'\\\r?\n' + Whitespace) + maybe(Comment) Name = r'\w+' Hexnumber = r'0[xX][0-9a-fA-F]+' Binnumber = r'0[bB][01]+' Octnumber = r'0[oO][0-7]+' Decnumber = r'(?:0+|[1-9][0-9]*)' Intnumber = group(Hexnumber, Binnumber, Octnumber, Decnumber) Exponent = r'[eE][-+]?[0-9]+' Pointfloat = group(r'[0-9]+\.[0-9]*', r'\.[0-9]+') + maybe(Exponent) Expfloat = r'[0-9]+' + Exponent Floatnumber = group(Pointfloat, Expfloat) Imagnumber = group(r'[0-9]+[jJ]', Floatnumber + r'[jJ]') Number = group(Imagnumber, Floatnumber, Intnumber) if sys.version_info.minor >= 3: StringPrefix = r'(?:[bB][rR]?|[rR][bB]?|[uU])?' else: StringPrefix = r'(?:[bB]?[rR]?)?' # Tail end of ' string. Single = r"[^'\\]*(?:\\.[^'\\]*)*'" # Tail end of " string. Double = r'[^"\\]*(?:\\.[^"\\]*)*"' # Tail end of ''' string. Single3 = r"[^'\\]*(?:(?:\\.|'(?!''))[^'\\]*)*'''" # Tail end of """ string. Double3 = r'[^"\\]*(?:(?:\\.|"(?!""))[^"\\]*)*"""' Triple = group(StringPrefix + "'''", StringPrefix + '"""') # Single-line ' or " string. String = group(StringPrefix + r"'[^\n'\\]*(?:\\.[^\n'\\]*)*'", StringPrefix + r'"[^\n"\\]*(?:\\.[^\n"\\]*)*"') # Because of leftmost-then-longest match semantics, be sure to put the # longest operators first (e.g., if = came before ==, == would get # recognized as two instances of =). Operator = group(r"\*\*=?", r">>=?", r"<<=?", r"!=", r"//=?", r"->", r"[+\-*/%&|^=<>]=?", r"~") Bracket = '[][(){}]' Special = group(r'\r?\n', r'\.\.\.', r'[:;.,@]') Funny = group(Operator, Bracket, Special) PlainToken = group(Number, Funny, String, Name) Token = Ignore + PlainToken # First (or only) line of ' or " string. ContStr = group(StringPrefix + r"'[^\n'\\]*(?:\\.[^\n'\\]*)*" + group("'", r'\\\r?\n'), StringPrefix + r'"[^\n"\\]*(?:\\.[^\n"\\]*)*' + group('"', r'\\\r?\n')) PseudoExtras = group(r'\\\r?\n', Comment, Triple) PseudoToken = Whitespace + group(PseudoExtras, Number, Funny, ContStr, Name) def _compile(expr): return re.compile(expr, re.UNICODE) tokenprog, pseudoprog, single3prog, double3prog = map( _compile, (Token, PseudoToken, Single3, Double3)) endprogs = {"'": _compile(Single), '"': _compile(Double), "'''": single3prog, '"""': double3prog, "r'''": single3prog, 'r"""': double3prog, "b'''": single3prog, 'b"""': double3prog, "R'''": single3prog, 'R"""': double3prog, "B'''": single3prog, 'B"""': double3prog, "br'''": single3prog, 'br"""': double3prog, "bR'''": single3prog, 'bR"""': double3prog, "Br'''": single3prog, 'Br"""': double3prog, "BR'''": single3prog, 'BR"""': double3prog, 'r': None, 'R': None, 'b': None, 'B': None} triple_quoted = {} for t in ("'''", '"""', "r'''", 'r"""', "R'''", 'R"""', "b'''", 'b"""', "B'''", 'B"""', "br'''", 'br"""', "Br'''", 'Br"""', "bR'''", 'bR"""', "BR'''", 'BR"""'): triple_quoted[t] = t single_quoted = {} for t in ("'", '"', "r'", 'r"', "R'", 'R"', "b'", 'b"', "B'", 'B"', "br'", 'br"', "Br'", 'Br"', "bR'", 'bR"', "BR'", 'BR"' ): single_quoted[t] = t if sys.version_info.minor >= 3: # Python 3.3 for _prefix in ['rb', 'rB', 'Rb', 'RB', 'u', 'U']: _t2 = _prefix+'"""' endprogs[_t2] = double3prog triple_quoted[_t2] = _t2 _t1 = _prefix + "'''" endprogs[_t1] = single3prog triple_quoted[_t1] = _t1 single_quoted[_prefix+'"'] = _prefix+'"' single_quoted[_prefix+"'"] = _prefix+"'" del _prefix, _t2, _t1 endprogs['u'] = None endprogs['U'] = None del _compile tabsize = 8 class TokenError(Exception): pass class StopTokenizing(Exception): pass class Untokenizer: def __init__(self): self.tokens = [] self.prev_row = 1 self.prev_col = 0 self.encoding = 'utf-8' def add_whitespace(self, tok_type, start): row, col = start assert row >= self.prev_row col_offset = col - self.prev_col if col_offset > 0: self.tokens.append(" " * col_offset) elif row > self.prev_row and tok_type not in (NEWLINE, NL, ENDMARKER): # Line was backslash-continued. self.tokens.append(" ") def untokenize(self, tokens): iterable = iter(tokens) for t in iterable: if len(t) == 2: self.compat(t, iterable) break tok_type, token, start, end = t[:4] if tok_type == ENCODING: self.encoding = token continue self.add_whitespace(tok_type, start) self.tokens.append(token) self.prev_row, self.prev_col = end if tok_type in (NEWLINE, NL): self.prev_row += 1 self.prev_col = 0 return "".join(self.tokens) def compat(self, token, iterable): # This import is here to avoid problems when the itertools # module is not built yet and tokenize is imported. from itertools import chain startline = False prevstring = False indents = [] toks_append = self.tokens.append for tok in chain([token], iterable): toknum, tokval = tok[:2] if toknum == ENCODING: self.encoding = tokval continue if toknum in (NAME, NUMBER): tokval += ' ' # Insert a space between two consecutive strings if toknum == STRING: if prevstring: tokval = ' ' + tokval prevstring = True else: prevstring = False if toknum == INDENT: indents.append(tokval) continue elif toknum == DEDENT: indents.pop() continue elif toknum in (NEWLINE, NL): startline = True elif startline and indents: toks_append(indents[-1]) startline = False toks_append(tokval) def untokenize(tokens): """ Convert ``tokens`` (an iterable) back into Python source code. Return a bytes object, encoded using the encoding specified by the last ENCODING token in ``tokens``, or UTF-8 if no ENCODING token is found. The result is guaranteed to tokenize back to match the input so that the conversion is lossless and round-trips are assured. The guarantee applies only to the token type and token string as the spacing between tokens (column positions) may change. :func:`untokenize` has two modes. If the input tokens are sequences of length 2 (``type``, ``string``) then spaces are added as necessary to preserve the round-trip property. If the input tokens are sequences of length 4 or more (``type``, ``string``, ``start``, ``end``), as returned by :func:`tokenize`, then spaces are added so that each token appears in the result at the position indicated by ``start`` and ``end``, if possible. """ return Untokenizer().untokenize(tokens) def _get_normal_name(orig_enc): """Imitates get_normal_name in tokenizer.c.""" # Only care about the first 12 characters. enc = orig_enc[:12].lower().replace("_", "-") if enc == "utf-8" or enc.startswith("utf-8-"): return "utf-8" if enc in ("latin-1", "iso-8859-1", "iso-latin-1") or \ enc.startswith(("latin-1-", "iso-8859-1-", "iso-latin-1-")): return "iso-8859-1" return orig_enc def detect_encoding(readline): """ The detect_encoding() function is used to detect the encoding that should be used to decode a Python source file. It requires one argment, readline, in the same way as the tokenize() generator. It will call readline a maximum of twice, and return the encoding used (as a string) and a list of any lines (left as bytes) it has read in. It detects the encoding from the presence of a utf-8 bom or an encoding cookie as specified in pep-0263. If both a bom and a cookie are present, but disagree, a SyntaxError will be raised. If the encoding cookie is an invalid charset, raise a SyntaxError. Note that if a utf-8 bom is found, 'utf-8-sig' is returned. If no encoding is specified, then the default of 'utf-8' will be returned. """ bom_found = False encoding = None default = 'utf-8' def read_or_stop(): try: return readline() except StopIteration: return b'' def find_cookie(line): try: # Decode as UTF-8. Either the line is an encoding declaration, # in which case it should be pure ASCII, or it must be UTF-8 # per default encoding. line_string = line.decode('utf-8') except UnicodeDecodeError: raise SyntaxError("invalid or missing encoding declaration") matches = cookie_re.findall(line_string) if not matches: return None encoding = _get_normal_name(matches[0]) try: codec = lookup(encoding) except LookupError: # This behaviour mimics the Python interpreter raise SyntaxError("unknown encoding: " + encoding) if bom_found: if encoding != 'utf-8': # This behaviour mimics the Python interpreter raise SyntaxError('encoding problem: utf-8') encoding += '-sig' return encoding first = read_or_stop() if first.startswith(BOM_UTF8): bom_found = True first = first[3:] default = 'utf-8-sig' if not first: return default, [] encoding = find_cookie(first) if encoding: return encoding, [first] second = read_or_stop() if not second: return default, [first] encoding = find_cookie(second) if encoding: return encoding, [first, second] return default, [first, second] def open(filename): """Open a file in read only mode using the encoding detected by detect_encoding(). """ buffer = builtins.open(filename, 'rb') encoding, lines = detect_encoding(buffer.readline) buffer.seek(0) text = TextIOWrapper(buffer, encoding, line_buffering=True) text.mode = 'r' return text def tokenize(readline): """ The tokenize() generator requires one argment, readline, which must be a callable object which provides the same interface as the readline() method of built-in file objects. Each call to the function should return one line of input as bytes. Alternately, readline can be a callable function terminating with StopIteration: readline = open(myfile, 'rb').__next__ # Example of alternate readline The generator produces 5-tuples with these members: the token type; the token string; a 2-tuple (srow, scol) of ints specifying the row and column where the token begins in the source; a 2-tuple (erow, ecol) of ints specifying the row and column where the token ends in the source; and the line on which the token was found. The line passed is the logical line; continuation lines are included. The first token sequence will always be an ENCODING token which tells you which encoding was used to decode the bytes stream. """ # This import is here to avoid problems when the itertools module is not # built yet and tokenize is imported. from itertools import chain, repeat encoding, consumed = detect_encoding(readline) rl_gen = iter(readline, b"") empty = repeat(b"") return _tokenize(chain(consumed, rl_gen, empty).__next__, encoding) def _tokenize(readline, encoding): lnum = parenlev = continued = 0 numchars = '0123456789' contstr, needcont = '', 0 contline = None indents = [0] if encoding is not None: if encoding == "utf-8-sig": # BOM will already have been stripped. encoding = "utf-8" yield TokenInfo(ENCODING, encoding, (0, 0), (0, 0), '') while True: # loop over lines in stream try: line = readline() except StopIteration: line = b'' if encoding is not None: line = line.decode(encoding) lnum += 1 pos, max = 0, len(line) if contstr: # continued string if not line: raise TokenError("EOF in multi-line string", strstart) endmatch = endprog.match(line) if endmatch: pos = end = endmatch.end(0) yield TokenInfo(STRING, contstr + line[:end], strstart, (lnum, end), contline + line) contstr, needcont = '', 0 contline = None elif needcont and line[-2:] != '\\\n' and line[-3:] != '\\\r\n': yield TokenInfo(ERRORTOKEN, contstr + line, strstart, (lnum, len(line)), contline) contstr = '' contline = None continue else: contstr = contstr + line contline = contline + line continue elif parenlev == 0 and not continued: # new statement if not line: break column = 0 while pos < max: # measure leading whitespace if line[pos] == ' ': column += 1 elif line[pos] == '\t': column = (column//tabsize + 1)*tabsize elif line[pos] == '\f': column = 0 else: break pos += 1 if pos == max: break if line[pos] in '#\r\n': # skip comments or blank lines if line[pos] == '#': comment_token = line[pos:].rstrip('\r\n') nl_pos = pos + len(comment_token) yield TokenInfo(COMMENT, comment_token, (lnum, pos), (lnum, pos + len(comment_token)), line) yield TokenInfo(NEWLINE, line[nl_pos:], (lnum, nl_pos), (lnum, len(line)), line) else: yield TokenInfo(NEWLINE, line[pos:], (lnum, pos), (lnum, len(line)), line) continue if column > indents[-1]: # count indents or dedents indents.append(column) yield TokenInfo(INDENT, line[:pos], (lnum, 0), (lnum, pos), line) while column < indents[-1]: if column not in indents: raise IndentationError( "unindent does not match any outer indentation level", ("", lnum, pos, line)) indents = indents[:-1] yield TokenInfo(DEDENT, '', (lnum, pos), (lnum, pos), line) else: # continued statement if not line: raise TokenError("EOF in multi-line statement", (lnum, 0)) continued = 0 while pos < max: pseudomatch = pseudoprog.match(line, pos) if pseudomatch: # scan for tokens start, end = pseudomatch.span(1) spos, epos, pos = (lnum, start), (lnum, end), end token, initial = line[start:end], line[start] if (initial in numchars or # ordinary number (initial == '.' and token != '.' and token != '...')): yield TokenInfo(NUMBER, token, spos, epos, line) elif initial in '\r\n': yield TokenInfo(NL if parenlev > 0 else NEWLINE, token, spos, epos, line) elif initial == '#': assert not token.endswith("\n") yield TokenInfo(COMMENT, token, spos, epos, line) elif token in triple_quoted: endprog = endprogs[token] endmatch = endprog.match(line, pos) if endmatch: # all on one line pos = endmatch.end(0) token = line[start:pos] yield TokenInfo(STRING, token, spos, (lnum, pos), line) else: strstart = (lnum, start) # multiple lines contstr = line[start:] contline = line break elif initial in single_quoted or \ token[:2] in single_quoted or \ token[:3] in single_quoted: if token[-1] == '\n': # continued string strstart = (lnum, start) endprog = (endprogs[initial] or endprogs[token[1]] or endprogs[token[2]]) contstr, needcont = line[start:], 1 contline = line break else: # ordinary string yield TokenInfo(STRING, token, spos, epos, line) elif initial.isidentifier(): # ordinary name yield TokenInfo(NAME, token, spos, epos, line) elif initial == '\\': # continued stmt continued = 1 else: if initial in '([{': parenlev += 1 elif initial in ')]}': parenlev -= 1 yield TokenInfo(OP, token, spos, epos, line) else: yield TokenInfo(ERRORTOKEN, line[pos], (lnum, pos), (lnum, pos+1), line) pos += 1 for indent in indents[1:]: # pop remaining indent levels yield TokenInfo(DEDENT, '', (lnum, 0), (lnum, 0), '') yield TokenInfo(ENDMARKER, '', (lnum, 0), (lnum, 0), '') # An undocumented, backwards compatible, API for all the places in the standard # library that expect to be able to use tokenize with strings def generate_tokens(readline): return _tokenize(readline, None) if __name__ == "__main__": # Quick sanity check s = b'''def parseline(self, line): """Parse the line into a command name and a string containing the arguments. Returns a tuple containing (command, args, line). 'command' and 'args' may be None if the line couldn't be parsed. """ line = line.strip() if not line: return None, None, line elif line[0] == '?': line = 'help ' + line[1:] elif line[0] == '!': if hasattr(self, 'do_shell'): line = 'shell ' + line[1:] else: return None, None, line i, n = 0, len(line) while i < n and line[i] in self.identchars: i = i+1 cmd, arg = line[:i], line[i:].strip() return cmd, arg, line ''' for tok in tokenize(iter(s.splitlines()).__next__): print(tok)