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- """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.
- """
- __author__ = 'Ka-Ping Yee <ping@lfw.org>'
- __credits__ = ('GvR, ESR, Tim Peters, Thomas Wouters, Fred Drake, '
- 'Skip Montanaro, Raymond Hettinger, Trent Nelson, '
- 'Michael Foord')
- from builtins import open as _builtin_open
- from codecs import lookup, BOM_UTF8
- import collections
- from io import TextIOWrapper
- import itertools as _itertools
- import re
- import sys
- from token import *
- from token import EXACT_TOKEN_TYPES
- cookie_re = re.compile(r'^[ \t\f]*#.*?coding[:=][ \t]*([-\w.]+)', re.ASCII)
- blank_re = re.compile(br'^[ \t\f]*(?:[#\r\n]|$)', re.ASCII)
- import token
- __all__ = token.__all__ + ["tokenize", "generate_tokens", "detect_encoding",
- "untokenize", "TokenInfo"]
- del token
- 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))
- @property
- def exact_type(self):
- if self.type == OP and self.string in EXACT_TOKEN_TYPES:
- return EXACT_TOKEN_TYPES[self.string]
- else:
- return self.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(?:_?0)*|[1-9](?:_?[0-9])*)'
- Intnumber = group(Hexnumber, Binnumber, Octnumber, Decnumber)
- Exponent = r'[eE][-+]?[0-9](?:_?[0-9])*'
- Pointfloat = group(r'[0-9](?:_?[0-9])*\.(?:[0-9](?:_?[0-9])*)?',
- r'\.[0-9](?:_?[0-9])*') + maybe(Exponent)
- Expfloat = r'[0-9](?:_?[0-9])*' + Exponent
- Floatnumber = group(Pointfloat, Expfloat)
- Imagnumber = group(r'[0-9](?:_?[0-9])*[jJ]', Floatnumber + r'[jJ]')
- Number = group(Imagnumber, Floatnumber, Intnumber)
- # Return the empty string, plus all of the valid string prefixes.
- def _all_string_prefixes():
- # The valid string prefixes. Only contain the lower case versions,
- # and don't contain any permutations (include 'fr', but not
- # 'rf'). The various permutations will be generated.
- _valid_string_prefixes = ['b', 'r', 'u', 'f', 'br', 'fr']
- # if we add binary f-strings, add: ['fb', 'fbr']
- result = {''}
- for prefix in _valid_string_prefixes:
- for t in _itertools.permutations(prefix):
- # create a list with upper and lower versions of each
- # character
- for u in _itertools.product(*[(c, c.upper()) for c in t]):
- result.add(''.join(u))
- return result
- def _compile(expr):
- return re.compile(expr, re.UNICODE)
- # Note that since _all_string_prefixes includes the empty string,
- # StringPrefix can be the empty string (making it optional).
- StringPrefix = group(*_all_string_prefixes())
- # 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"\\]*)*"')
- # Sorting in reverse order puts the long operators before their prefixes.
- # Otherwise if = came before ==, == would get recognized as two instances
- # of =.
- Special = group(*map(re.escape, sorted(EXACT_TOKEN_TYPES, reverse=True)))
- Funny = group(r'\r?\n', 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|\Z', Comment, Triple)
- PseudoToken = Whitespace + group(PseudoExtras, Number, Funny, ContStr, Name)
- # For a given string prefix plus quotes, endpats maps it to a regex
- # to match the remainder of that string. _prefix can be empty, for
- # a normal single or triple quoted string (with no prefix).
- endpats = {}
- for _prefix in _all_string_prefixes():
- endpats[_prefix + "'"] = Single
- endpats[_prefix + '"'] = Double
- endpats[_prefix + "'''"] = Single3
- endpats[_prefix + '"""'] = Double3
- # A set of all of the single and triple quoted string prefixes,
- # including the opening quotes.
- single_quoted = set()
- triple_quoted = set()
- for t in _all_string_prefixes():
- for u in (t + '"', t + "'"):
- single_quoted.add(u)
- for u in (t + '"""', t + "'''"):
- triple_quoted.add(u)
- 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 = None
- def add_whitespace(self, start):
- row, col = start
- if row < self.prev_row or row == self.prev_row and col < self.prev_col:
- raise ValueError("start ({},{}) precedes previous end ({},{})"
- .format(row, col, self.prev_row, self.prev_col))
- row_offset = row - self.prev_row
- if row_offset:
- self.tokens.append("\\\n" * row_offset)
- self.prev_col = 0
- col_offset = col - self.prev_col
- if col_offset:
- self.tokens.append(" " * col_offset)
- def untokenize(self, iterable):
- it = iter(iterable)
- indents = []
- startline = False
- for t in it:
- if len(t) == 2:
- self.compat(t, it)
- break
- tok_type, token, start, end, line = t
- if tok_type == ENCODING:
- self.encoding = token
- continue
- if tok_type == ENDMARKER:
- break
- if tok_type == INDENT:
- indents.append(token)
- continue
- elif tok_type == DEDENT:
- indents.pop()
- self.prev_row, self.prev_col = end
- continue
- elif tok_type in (NEWLINE, NL):
- startline = True
- elif startline and indents:
- indent = indents[-1]
- if start[1] >= len(indent):
- self.tokens.append(indent)
- self.prev_col = len(indent)
- startline = False
- self.add_whitespace(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):
- indents = []
- toks_append = self.tokens.append
- startline = token[0] in (NEWLINE, NL)
- prevstring = False
- for tok in _itertools.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(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
- only two tokens are passed, the resulting output is poor.
- Round-trip invariant for full input:
- Untokenized source will match input source exactly
- Round-trip invariant for limited input:
- # Output bytes will tokenize back to the input
- t1 = [tok[:2] for tok in tokenize(f.readline)]
- newcode = untokenize(t1)
- readline = BytesIO(newcode).readline
- t2 = [tok[:2] for tok in tokenize(readline)]
- assert t1 == t2
- """
- ut = Untokenizer()
- 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 argument, 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.
- """
- try:
- filename = readline.__self__.name
- except AttributeError:
- filename = None
- 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:
- msg = "invalid or missing encoding declaration"
- if filename is not None:
- msg = '{} for {!r}'.format(msg, filename)
- raise SyntaxError(msg)
- match = cookie_re.match(line_string)
- if not match:
- return None
- encoding = _get_normal_name(match.group(1))
- try:
- codec = lookup(encoding)
- except LookupError:
- # This behaviour mimics the Python interpreter
- if filename is None:
- msg = "unknown encoding: " + encoding
- else:
- msg = "unknown encoding for {!r}: {}".format(filename,
- encoding)
- raise SyntaxError(msg)
- if bom_found:
- if encoding != 'utf-8':
- # This behaviour mimics the Python interpreter
- if filename is None:
- msg = 'encoding problem: utf-8'
- else:
- msg = 'encoding problem for {!r}: utf-8'.format(filename)
- raise SyntaxError(msg)
- 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]
- if not blank_re.match(first):
- return default, [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 = _builtin_open(filename, 'rb')
- try:
- encoding, lines = detect_encoding(buffer.readline)
- buffer.seek(0)
- text = TextIOWrapper(buffer, encoding, line_buffering=True)
- text.mode = 'r'
- return text
- except:
- buffer.close()
- raise
- def tokenize(readline):
- """
- The tokenize() generator requires one argument, 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. Alternatively, 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
- physical line.
- The first token sequence will always be an ENCODING token
- which tells you which encoding was used to decode the bytes stream.
- """
- encoding, consumed = detect_encoding(readline)
- empty = _itertools.repeat(b"")
- rl_gen = _itertools.chain(consumed, iter(readline, b""), empty)
- return _tokenize(rl_gen.__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), '')
- last_line = b''
- line = b''
- while True: # loop over lines in stream
- try:
- # We capture the value of the line variable here because
- # readline uses the empty string '' to signal end of input,
- # hence `line` itself will always be overwritten at the end
- # of this loop.
- last_line = line
- 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')
- yield TokenInfo(COMMENT, comment_token,
- (lnum, pos), (lnum, pos + len(comment_token)), line)
- pos += len(comment_token)
- yield TokenInfo(NL, 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",
- ("<tokenize>", 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 = _compile(PseudoToken).match(line, pos)
- if pseudomatch: # scan for tokens
- start, end = pseudomatch.span(1)
- spos, epos, pos = (lnum, start), (lnum, end), end
- if start == end:
- continue
- 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':
- if parenlev > 0:
- yield TokenInfo(NL, token, spos, epos, line)
- else:
- yield TokenInfo(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 = _compile(endpats[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
- # Check up to the first 3 chars of the token to see if
- # they're in the single_quoted set. If so, they start
- # a string.
- # We're using the first 3, because we're looking for
- # "rb'" (for example) at the start of the token. If
- # we switch to longer prefixes, this needs to be
- # adjusted.
- # Note that initial == token[:1].
- # Also note that single quote checking must come after
- # triple quote checking (above).
- 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)
- # Again, using the first 3 chars of the
- # token. This is looking for the matching end
- # regex for the correct type of quote
- # character. So it's really looking for
- # endpats["'"] or endpats['"'], by trying to
- # skip string prefix characters, if any.
- endprog = _compile(endpats.get(initial) or
- endpats.get(token[1]) or
- endpats.get(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
- # Add an implicit NEWLINE if the input doesn't end in one
- if last_line and last_line[-1] not in '\r\n' and not last_line.strip().startswith("#"):
- yield TokenInfo(NEWLINE, '', (lnum - 1, len(last_line)), (lnum - 1, len(last_line) + 1), '')
- for indent in indents[1:]: # pop remaining indent levels
- yield TokenInfo(DEDENT, '', (lnum, 0), (lnum, 0), '')
- yield TokenInfo(ENDMARKER, '', (lnum, 0), (lnum, 0), '')
- def generate_tokens(readline):
- """Tokenize a source reading Python code as unicode strings.
- This has the same API as tokenize(), except that it expects the *readline*
- callable to return str objects instead of bytes.
- """
- return _tokenize(readline, None)
- def main():
- import argparse
- # Helper error handling routines
- def perror(message):
- sys.stderr.write(message)
- sys.stderr.write('\n')
- def error(message, filename=None, location=None):
- if location:
- args = (filename,) + location + (message,)
- perror("%s:%d:%d: error: %s" % args)
- elif filename:
- perror("%s: error: %s" % (filename, message))
- else:
- perror("error: %s" % message)
- sys.exit(1)
- # Parse the arguments and options
- parser = argparse.ArgumentParser(prog='python -m tokenize')
- parser.add_argument(dest='filename', nargs='?',
- metavar='filename.py',
- help='the file to tokenize; defaults to stdin')
- parser.add_argument('-e', '--exact', dest='exact', action='store_true',
- help='display token names using the exact type')
- args = parser.parse_args()
- try:
- # Tokenize the input
- if args.filename:
- filename = args.filename
- with _builtin_open(filename, 'rb') as f:
- tokens = list(tokenize(f.readline))
- else:
- filename = "<stdin>"
- tokens = _tokenize(sys.stdin.readline, None)
- # Output the tokenization
- for token in tokens:
- token_type = token.type
- if args.exact:
- token_type = token.exact_type
- token_range = "%d,%d-%d,%d:" % (token.start + token.end)
- print("%-20s%-15s%-15r" %
- (token_range, tok_name[token_type], token.string))
- except IndentationError as err:
- line, column = err.args[1][1:3]
- error(err.args[0], filename, (line, column))
- except TokenError as err:
- line, column = err.args[1]
- error(err.args[0], filename, (line, column))
- except SyntaxError as err:
- error(err, filename)
- except OSError as err:
- error(err)
- except KeyboardInterrupt:
- print("interrupted\n")
- except Exception as err:
- perror("unexpected error: %s" % err)
- raise
- if __name__ == "__main__":
- main()
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