"""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

from itertools import chain

import itertools as _itertools

import re

import sys

from token import *

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", "detect_encoding",

"untokenize", "TokenInfo"]

del token

EXACT_TOKEN_TYPES = {

'(': LPAR,

')': RPAR,

'[': LSQB,

']': RSQB,

':': COLON,

',': COMMA,

';': SEMI,

'+': PLUS,

'-': MINUS,

'*': STAR,

'/': SLASH,

'|': VBAR,

'&': AMPER,

'<': LESS,

'>': GREATER,

'=': EQUAL,

'.': DOT,

'%': PERCENT,

'{': LBRACE,

'}': RBRACE,

'==': EQEQUAL,

'!=': NOTEQUAL,

'<=': LESSEQUAL,

'>=': GREATEREQUAL,

'~': TILDE,

'^': CIRCUMFLEX,

'<<': LEFTSHIFT,

'>>': RIGHTSHIFT,

'**': DOUBLESTAR,

'+=': PLUSEQUAL,

'-=': MINEQUAL,

'*=': STAREQUAL,

'/=': SLASHEQUAL,

'%=': PERCENTEQUAL,

'&=': AMPEREQUAL,

'|=': VBAREQUAL,

'^=': CIRCUMFLEXEQUAL,

'<<=': LEFTSHIFTEQUAL,

'>>=': RIGHTSHIFTEQUAL,

'**=': DOUBLESTAREQUAL,

'//': DOUBLESLASH,

'//=': DOUBLESLASHEQUAL,

'...': ELLIPSIS,

'->': RARROW,

'@': AT,

'@=': ATEQUAL,

}

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"\\]*)*"')

# 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|\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 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

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), '')

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':

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), '')

# 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)

def main():

import argparse

# Helper error handling routines

def perror(message):

print(message, file=sys.stderr)

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()