diff options
Diffstat (limited to 'Lib/tokenize.py')
| -rw-r--r-- | Lib/tokenize.py | 383 |
1 files changed, 259 insertions, 124 deletions
diff --git a/Lib/tokenize.py b/Lib/tokenize.py index ca7b07493cf..29c9e29b30f 100644 --- a/Lib/tokenize.py +++ b/Lib/tokenize.py @@ -1,9 +1,12 @@ """Tokenization help for Python programs. -generate_tokens(readline) is a generator that breaks a stream of -text into Python tokens. It accepts a readline-like method which is called -repeatedly to get the next line of input (or "" for EOF). It generates -5-tuples with these members: +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) @@ -13,53 +16,63 @@ repeatedly to get the next line of input (or "" for EOF). It generates 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 - -Older entry points - tokenize_loop(readline, tokeneater) - tokenize(readline, tokeneater=printtoken) -are the same, except instead of generating tokens, tokeneater is a callback -function to which the 5 fields described above are passed as 5 arguments, -each time a new token is found.""" +operators. Additionally, all token lists start with an ENCODING token +which tells you which encoding was used to decode the bytes stream. +""" __author__ = 'Ka-Ping Yee <ping@lfw.org>' __credits__ = ('GvR, ESR, Tim Peters, Thomas Wouters, Fred Drake, ' - 'Skip Montanaro, Raymond Hettinger') - -import string, re + '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__ = [x for x in dir(token) if not x.startswith("_")] -__all__ += ["COMMENT", "tokenize", "generate_tokens", "NL", "untokenize"] -del x +__all__ = token.__all__ + ["COMMENT", "tokenize", "detect_encoding", + "NL", "untokenize", "ENCODING", "TokenInfo"] del token COMMENT = N_TOKENS tok_name[COMMENT] = 'COMMENT' NL = N_TOKENS + 1 tok_name[NL] = 'NL' -N_TOKENS += 2 +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'[a-zA-Z_]\w*' +Name = r'\w+' -Hexnumber = r'0[xX][\da-fA-F]+[lL]?' -Octnumber = r'(0[oO][0-7]+)|(0[0-7]*)[lL]?' -Binnumber = r'0[bB][01]+[lL]?' -Decnumber = r'[1-9]\d*[lL]?' +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][-+]?\d+' -Pointfloat = group(r'\d+\.\d*', r'\.\d+') + maybe(Exponent) -Expfloat = r'\d+' + Exponent +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'\d+[jJ]', Floatnumber + r'[jJ]') +Imagnumber = group(r'[0-9]+[jJ]', Floatnumber + r'[jJ]') Number = group(Imagnumber, Floatnumber, Intnumber) # Tail end of ' string. @@ -70,61 +83,54 @@ Double = r'[^"\\]*(?:\\.[^"\\]*)*"' Single3 = r"[^'\\]*(?:(?:\\.|'(?!''))[^'\\]*)*'''" # Tail end of """ string. Double3 = r'[^"\\]*(?:(?:\\.|"(?!""))[^"\\]*)*"""' -Triple = group("[uUbB]?[rR]?'''", '[uUbB]?[rR]?"""') +Triple = group("[bB]?[rR]?'''", '[bB]?[rR]?"""') # Single-line ' or " string. -String = group(r"[uUbB]?[rR]?'[^\n'\\]*(?:\\.[^\n'\\]*)*'", - r'[uUbB]?[rR]?"[^\n"\\]*(?:\\.[^\n"\\]*)*"') +String = group(r"[bB]?[rR]?'[^\n'\\]*(?:\\.[^\n'\\]*)*'", + r'[bB]?[rR]?"[^\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"//=?", +Operator = group(r"\*\*=?", r">>=?", r"<<=?", r"!=", + r"//=?", r"->", r"[+\-*/%&|^=<>]=?", r"~") Bracket = '[][(){}]' -Special = group(r'\r?\n', r'[:;.,`@]') +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(r"[uUbB]?[rR]?'[^\n'\\]*(?:\\.[^\n'\\]*)*" + +ContStr = group(r"[bB]?[rR]?'[^\n'\\]*(?:\\.[^\n'\\]*)*" + group("'", r'\\\r?\n'), - r'[uUbB]?[rR]?"[^\n"\\]*(?:\\.[^\n"\\]*)*' + + r'[bB]?[rR]?"[^\n"\\]*(?:\\.[^\n"\\]*)*' + group('"', r'\\\r?\n')) PseudoExtras = group(r'\\\r?\n|\Z', Comment, Triple) PseudoToken = Whitespace + group(PseudoExtras, Number, Funny, ContStr, Name) +def _compile(expr): + return re.compile(expr, re.UNICODE) + tokenprog, pseudoprog, single3prog, double3prog = map( - re.compile, (Token, PseudoToken, Single3, Double3)) -endprogs = {"'": re.compile(Single), '"': re.compile(Double), + _compile, (Token, PseudoToken, Single3, Double3)) +endprogs = {"'": _compile(Single), '"': _compile(Double), "'''": single3prog, '"""': double3prog, "r'''": single3prog, 'r"""': double3prog, - "u'''": single3prog, 'u"""': double3prog, - "ur'''": single3prog, 'ur"""': double3prog, - "R'''": single3prog, 'R"""': double3prog, - "U'''": single3prog, 'U"""': double3prog, - "uR'''": single3prog, 'uR"""': double3prog, - "Ur'''": single3prog, 'Ur"""': double3prog, - "UR'''": single3prog, 'UR"""': double3prog, "b'''": single3prog, 'b"""': double3prog, "br'''": single3prog, 'br"""': double3prog, + "R'''": single3prog, 'R"""': double3prog, "B'''": single3prog, 'B"""': double3prog, "bR'''": single3prog, 'bR"""': double3prog, "Br'''": single3prog, 'Br"""': double3prog, "BR'''": single3prog, 'BR"""': double3prog, - 'r': None, 'R': None, 'u': None, 'U': None, - 'b': None, 'B': None} + 'r': None, 'R': None, 'b': None, 'B': None} triple_quoted = {} for t in ("'''", '"""', "r'''", 'r"""', "R'''", 'R"""', - "u'''", 'u"""', "U'''", 'U"""', - "ur'''", 'ur"""', "Ur'''", 'Ur"""', - "uR'''", 'uR"""', "UR'''", 'UR"""', "b'''", 'b"""', "B'''", 'B"""', "br'''", 'br"""', "Br'''", 'Br"""', "bR'''", 'bR"""', "BR'''", 'BR"""'): @@ -132,48 +138,19 @@ for t in ("'''", '"""', single_quoted = {} for t in ("'", '"', "r'", 'r"', "R'", 'R"', - "u'", 'u"', "U'", 'U"', - "ur'", 'ur"', "Ur'", 'Ur"', - "uR'", 'uR"', "UR'", 'UR"', "b'", 'b"', "B'", 'B"', "br'", 'br"', "Br'", 'Br"', "bR'", 'bR"', "BR'", 'BR"' ): single_quoted[t] = t +del _compile + tabsize = 8 class TokenError(Exception): pass class StopTokenizing(Exception): pass -def printtoken(type, token, srow_scol, erow_ecol, line): # for testing - srow, scol = srow_scol - erow, ecol = erow_ecol - print "%d,%d-%d,%d:\t%s\t%s" % \ - (srow, scol, erow, ecol, tok_name[type], repr(token)) - -def tokenize(readline, tokeneater=printtoken): - """ - The tokenize() function accepts two parameters: one representing the - input stream, and one providing an output mechanism for tokenize(). - - The first parameter, readline, 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 a string. - - The second parameter, tokeneater, must also be a callable object. It is - called once for each token, with five arguments, corresponding to the - tuples generated by generate_tokens(). - """ - try: - tokenize_loop(readline, tokeneater) - except StopTokenizing: - pass - -# backwards compatible interface -def tokenize_loop(readline, tokeneater): - for token_info in generate_tokens(readline): - tokeneater(*token_info) class Untokenizer: @@ -181,6 +158,7 @@ class Untokenizer: self.tokens = [] self.prev_row = 1 self.prev_col = 0 + self.encoding = None def add_whitespace(self, start): row, col = start @@ -195,6 +173,9 @@ class Untokenizer: self.compat(t, iterable) break tok_type, token, start, end, line = t + if tok_type == ENCODING: + self.encoding = token + continue self.add_whitespace(start) self.tokens.append(token) self.prev_row, self.prev_col = end @@ -208,6 +189,7 @@ class Untokenizer: indents = [] toks_append = self.tokens.append toknum, tokval = token + if toknum in (NAME, NUMBER): tokval += ' ' if toknum in (NEWLINE, NL): @@ -215,6 +197,9 @@ class Untokenizer: prevstring = False for tok in iterable: toknum, tokval = tok[:2] + if toknum == ENCODING: + self.encoding = tokval + continue if toknum in (NAME, NUMBER): tokval += ' ' @@ -240,8 +225,11 @@ class Untokenizer: startline = False toks_append(tokval) + def untokenize(iterable): """Transform tokens back into Python source code. + It returns a bytes object, encoded using the ENCODING + token, which is the first token sequence output by tokenize. Each element returned by the iterable must be a token sequence with at least two elements, a token number and token value. If @@ -251,58 +239,181 @@ def untokenize(iterable): Untokenized source will match input source exactly Round-trip invariant for limited intput: - # Output text will tokenize the back to the input - t1 = [tok[:2] for tok in generate_tokens(f.readline)] + # Output bytes will tokenize the back to the input + t1 = [tok[:2] for tok in tokenize(f.readline)] newcode = untokenize(t1) - readline = iter(newcode.splitlines(1)).next - t2 = [tok[:2] for tok in generate_tokens(readline)] + readline = BytesIO(newcode).readline + t2 = [tok[:2] for tok in tokenize(readline)] assert t1 == t2 """ ut = Untokenizer() - return ut.untokenize(iterable) + out = ut.untokenize(iterable) + if ut.encoding is not None: + out = out.encode(ut.encoding) + return out + + +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. -def generate_tokens(readline): + 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 generate_tokens() generator requires one argment, readline, which + 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 a string. Alternately, readline + 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).next # Example of alternate readline + 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 + 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 - namechars, numchars = string.ascii_letters + '_', '0123456789' + numchars = '0123456789' contstr, needcont = '', 0 contline = None indents = [0] - while 1: # loop over lines in stream + 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 = '' + 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) + raise TokenError("EOF in multi-line string", strstart) endmatch = endprog.match(line) if endmatch: pos = end = endmatch.end(0) - yield (STRING, contstr + line[:end], + 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 (ERRORTOKEN, contstr + line, + yield TokenInfo(ERRORTOKEN, contstr + line, strstart, (lnum, len(line)), contline) contstr = '' contline = None @@ -332,29 +443,29 @@ def generate_tokens(readline): if line[pos] == '#': comment_token = line[pos:].rstrip('\r\n') nl_pos = pos + len(comment_token) - yield (COMMENT, comment_token, + yield TokenInfo(COMMENT, comment_token, (lnum, pos), (lnum, pos + len(comment_token)), line) - yield (NL, line[nl_pos:], + yield TokenInfo(NL, line[nl_pos:], (lnum, nl_pos), (lnum, len(line)), line) else: - yield ((NL, COMMENT)[line[pos] == '#'], line[pos:], + yield TokenInfo((NL, COMMENT)[line[pos] == '#'], line[pos:], (lnum, pos), (lnum, len(line)), line) continue if column > indents[-1]: # count indents or dedents indents.append(column) - yield (INDENT, line[:pos], (lnum, 0), (lnum, pos), line) + 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", ("<tokenize>", lnum, pos, line)) indents = indents[:-1] - yield (DEDENT, '', (lnum, pos), (lnum, pos), line) + yield TokenInfo(DEDENT, '', (lnum, pos), (lnum, pos), line) else: # continued statement if not line: - raise TokenError, ("EOF in multi-line statement", (lnum, 0)) + raise TokenError("EOF in multi-line statement", (lnum, 0)) continued = 0 while pos < max: @@ -366,22 +477,22 @@ def generate_tokens(readline): continue token, initial = line[start:end], line[start] - if initial in numchars or \ - (initial == '.' and token != '.'): # ordinary number - yield (NUMBER, token, spos, epos, line) + 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 (NL if parenlev > 0 else NEWLINE, + yield TokenInfo(NL if parenlev > 0 else NEWLINE, token, spos, epos, line) elif initial == '#': assert not token.endswith("\n") - yield (COMMENT, token, spos, epos, line) + 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 (STRING, token, spos, (lnum, pos), line) + yield TokenInfo(STRING, token, spos, (lnum, pos), line) else: strstart = (lnum, start) # multiple lines contstr = line[start:] @@ -398,9 +509,9 @@ def generate_tokens(readline): contline = line break else: # ordinary string - yield (STRING, token, spos, epos, line) - elif initial in namechars: # ordinary name - yield (NAME, token, spos, epos, line) + 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: @@ -408,19 +519,43 @@ def generate_tokens(readline): parenlev += 1 elif initial in ')]}': parenlev -= 1 - yield (OP, token, spos, epos, line) + yield TokenInfo(OP, token, spos, epos, line) else: - yield (ERRORTOKEN, line[pos], + yield TokenInfo(ERRORTOKEN, line[pos], (lnum, pos), (lnum, pos+1), line) pos += 1 for indent in indents[1:]: # pop remaining indent levels - yield (DEDENT, '', (lnum, 0), (lnum, 0), '') - yield (ENDMARKER, '', (lnum, 0), (lnum, 0), '') - -if __name__ == '__main__': # testing - import sys - if len(sys.argv) > 1: - tokenize(open(sys.argv[1]).readline) - else: - tokenize(sys.stdin.readline) + 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) |