465 lines
17 KiB
Python
465 lines
17 KiB
Python
"""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. Aditionally, 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')
|
|
|
|
import re, string, sys
|
|
from token import *
|
|
from codecs import lookup
|
|
from itertools import chain, repeat
|
|
cookie_re = re.compile("coding[:=]\s*([-\w.]+)")
|
|
|
|
import token
|
|
__all__ = [x for x in dir(token) if x[0] != '_'] + ["COMMENT", "tokenize",
|
|
"detect_encoding", "NL", "untokenize", "ENCODING"]
|
|
del token
|
|
|
|
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
|
|
|
|
def group(*choices): return '(' + '|'.join(choices) + ')'
|
|
def any(*choices): return group(*choices) + '*'
|
|
def maybe(*choices): return group(*choices) + '?'
|
|
|
|
Whitespace = r'[ \f\t]*'
|
|
Comment = r'#[^\r\n]*'
|
|
Ignore = Whitespace + any(r'\\\r?\n' + Whitespace) + maybe(Comment)
|
|
Name = r'[a-zA-Z_]\w*'
|
|
|
|
Hexnumber = r'0[xX][\da-fA-F]+'
|
|
Binnumber = r'0[bB][01]+'
|
|
Octnumber = r'0[oO][0-7]+'
|
|
Decnumber = r'(?:0+|[1-9]\d*)'
|
|
Intnumber = group(Hexnumber, Binnumber, Octnumber, Decnumber)
|
|
Exponent = r'[eE][-+]?\d+'
|
|
Pointfloat = group(r'\d+\.\d*', r'\.\d+') + maybe(Exponent)
|
|
Expfloat = r'\d+' + Exponent
|
|
Floatnumber = group(Pointfloat, Expfloat)
|
|
Imagnumber = group(r'\d+[jJ]', Floatnumber + r'[jJ]')
|
|
Number = group(Imagnumber, Floatnumber, Intnumber)
|
|
|
|
# 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("[bB]?[rR]?'''", '[bB]?[rR]?"""')
|
|
# Single-line ' or " string.
|
|
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"->",
|
|
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(r"[bB]?[rR]?'[^\n'\\]*(?:\\.[^\n'\\]*)*" +
|
|
group("'", r'\\\r?\n'),
|
|
r'[bB]?[rR]?"[^\n"\\]*(?:\\.[^\n"\\]*)*' +
|
|
group('"', r'\\\r?\n'))
|
|
PseudoExtras = group(r'\\\r?\n', Comment, Triple)
|
|
PseudoToken = Whitespace + group(PseudoExtras, Number, Funny, ContStr, Name)
|
|
|
|
tokenprog, pseudoprog, single3prog, double3prog = map(
|
|
re.compile, (Token, PseudoToken, Single3, Double3))
|
|
endprogs = {"'": re.compile(Single), '"': re.compile(Double),
|
|
"'''": single3prog, '"""': double3prog,
|
|
"r'''": single3prog, 'r"""': 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, '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
|
|
|
|
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
|
|
assert row <= self.prev_row
|
|
col_offset = col - self.prev_col
|
|
if col_offset:
|
|
self.tokens.append(" " * col_offset)
|
|
|
|
def untokenize(self, iterable):
|
|
for t in iterable:
|
|
if len(t) == 2:
|
|
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
|
|
if tok_type in (NEWLINE, NL):
|
|
self.prev_row += 1
|
|
self.prev_col = 0
|
|
return "".join(self.tokens)
|
|
|
|
def compat(self, token, iterable):
|
|
startline = False
|
|
indents = []
|
|
toks_append = self.tokens.append
|
|
toknum, tokval = token
|
|
|
|
if toknum in (NAME, NUMBER):
|
|
tokval += ' '
|
|
if toknum in (NEWLINE, NL):
|
|
startline = True
|
|
for tok in iterable:
|
|
toknum, tokval = tok[:2]
|
|
if toknum == ENCODING:
|
|
self.encoding = tokval
|
|
continue
|
|
|
|
if toknum in (NAME, NUMBER):
|
|
tokval += ' '
|
|
|
|
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 intput:
|
|
# Output bytes will tokenize the 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 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 no encoding is specified, then the default of 'utf-8' will be returned.
|
|
"""
|
|
utf8_bom = b'\xef\xbb\xbf'
|
|
bom_found = False
|
|
encoding = None
|
|
def read_or_stop():
|
|
try:
|
|
return readline()
|
|
except StopIteration:
|
|
return b''
|
|
|
|
def find_cookie(line):
|
|
try:
|
|
line_string = line.decode('ascii')
|
|
except UnicodeDecodeError:
|
|
pass
|
|
else:
|
|
matches = cookie_re.findall(line_string)
|
|
if matches:
|
|
encoding = matches[0]
|
|
if bom_found and lookup(encoding).name != 'utf-8':
|
|
# This behaviour mimics the Python interpreter
|
|
raise SyntaxError('encoding problem: utf-8')
|
|
return encoding
|
|
|
|
first = read_or_stop()
|
|
if first.startswith(utf8_bom):
|
|
bom_found = True
|
|
first = first[3:]
|
|
if not first:
|
|
return 'utf-8', []
|
|
|
|
encoding = find_cookie(first)
|
|
if encoding:
|
|
return encoding, [first]
|
|
|
|
second = read_or_stop()
|
|
if not second:
|
|
return 'utf-8', [first]
|
|
|
|
encoding = find_cookie(second)
|
|
if encoding:
|
|
return encoding, [first, second]
|
|
|
|
return 'utf-8', [first, second]
|
|
|
|
|
|
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.
|
|
"""
|
|
encoding, consumed = detect_encoding(readline)
|
|
def readline_generator():
|
|
while True:
|
|
try:
|
|
yield readline()
|
|
except StopIteration:
|
|
return
|
|
chained = chain(consumed, readline_generator())
|
|
return _tokenize(chained.__next__, encoding)
|
|
|
|
|
|
def _tokenize(readline, encoding):
|
|
lnum = parenlev = continued = 0
|
|
namechars, numchars = string.ascii_letters + '_', '0123456789'
|
|
contstr, needcont = '', 0
|
|
contline = None
|
|
indents = [0]
|
|
|
|
if encoding is not None:
|
|
yield (ENCODING, encoding, (0, 0), (0, 0), '')
|
|
while 1: # loop over lines in stream
|
|
try:
|
|
line = readline()
|
|
except StopIteration:
|
|
line = b''
|
|
|
|
if encoding is not None:
|
|
line = line.decode(encoding)
|
|
lnum = 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 (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,
|
|
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 = column + 1
|
|
elif line[pos] == '\t': column = (column/tabsize + 1)*tabsize
|
|
elif line[pos] == '\f': column = 0
|
|
else: break
|
|
pos = 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 (COMMENT, comment_token,
|
|
(lnum, pos), (lnum, pos + len(comment_token)), line)
|
|
yield (NL, line[nl_pos:],
|
|
(lnum, nl_pos), (lnum, len(line)), line)
|
|
else:
|
|
yield ((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)
|
|
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)
|
|
|
|
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 (NUMBER, token, spos, epos, line)
|
|
elif initial in '\r\n':
|
|
yield (NL if parenlev > 0 else NEWLINE,
|
|
token, spos, epos, line)
|
|
elif initial == '#':
|
|
assert not token.endswith("\n")
|
|
yield (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)
|
|
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 (STRING, token, spos, epos, line)
|
|
elif initial in namechars: # ordinary name
|
|
yield (NAME, token, spos, epos, line)
|
|
elif initial == '\\': # continued stmt
|
|
continued = 1
|
|
else:
|
|
if initial in '([{': parenlev = parenlev + 1
|
|
elif initial in ')]}': parenlev = parenlev - 1
|
|
yield (OP, token, spos, epos, line)
|
|
else:
|
|
yield (ERRORTOKEN, line[pos],
|
|
(lnum, pos), (lnum, pos+1), line)
|
|
pos = pos + 1
|
|
|
|
for indent in indents[1:]: # pop remaining indent levels
|
|
yield (DEDENT, '', (lnum, 0), (lnum, 0), '')
|
|
yield (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)
|