219 lines
9.1 KiB
Python
219 lines
9.1 KiB
Python
"""Tokenization help for Python programs.
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This module exports a function called 'tokenize()' that breaks a stream of
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text into Python tokens. It accepts a readline-like method which is called
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repeatedly to get the next line of input (or "" for EOF) and a "token-eater"
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function which is called once for each token found. The latter function is
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passed the token type, a string containing the token, the starting and
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ending (row, column) coordinates of the token, and the original line. It is
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designed to match the working of the Python tokenizer exactly, except that
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it produces COMMENT tokens for comments and gives type OP for all operators."""
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__version__ = "Ka-Ping Yee, 26 October 1997; patched, GvR 3/30/98"
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import string, re
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from token import *
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COMMENT = N_TOKENS
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tok_name[COMMENT] = 'COMMENT'
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NL = N_TOKENS + 1
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tok_name[NL] = 'NL'
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# Changes from 1.3:
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# Ignore now accepts \f as whitespace. Operator now includes '**'.
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# Ignore and Special now accept \n or \r\n at the end of a line.
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# Imagnumber is new. Expfloat is corrected to reject '0e4'.
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# Note: to quote a backslash in a regex, it must be doubled in a r'aw' string.
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def group(*choices): return '(' + string.join(choices, '|') + ')'
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def any(*choices): return apply(group, choices) + '*'
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def maybe(*choices): return apply(group, choices) + '?'
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Whitespace = r'[ \f\t]*'
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Comment = r'#[^\r\n]*'
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Ignore = Whitespace + any(r'\\\r?\n' + Whitespace) + maybe(Comment)
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Name = r'[a-zA-Z_]\w*'
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Hexnumber = r'0[xX][\da-fA-F]*[lL]?'
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Octnumber = r'0[0-7]*[lL]?'
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Decnumber = r'[1-9]\d*[lL]?'
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Intnumber = group(Hexnumber, Octnumber, Decnumber)
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Exponent = r'[eE][-+]?\d+'
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Pointfloat = group(r'\d+\.\d*', r'\.\d+') + maybe(Exponent)
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Expfloat = r'[1-9]\d*' + Exponent
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Floatnumber = group(Pointfloat, Expfloat)
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Imagnumber = group(r'0[jJ]', r'[1-9]\d*[jJ]', Floatnumber + r'[jJ]')
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Number = group(Imagnumber, Floatnumber, Intnumber)
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# Tail end of ' string.
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Single = r"[^'\\]*(?:\\.[^'\\]*)*'"
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# Tail end of " string.
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Double = r'[^"\\]*(?:\\.[^"\\]*)*"'
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# Tail end of ''' string.
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Single3 = r"[^'\\]*(?:(?:\\.|'(?!''))[^'\\]*)*'''"
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# Tail end of """ string.
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Double3 = r'[^"\\]*(?:(?:\\.|"(?!""))[^"\\]*)*"""'
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Triple = group("[rR]?'''", '[rR]?"""')
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# Single-line ' or " string.
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String = group(r"[rR]?'[^\n'\\]*(?:\\.[^\n'\\]*)*'",
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r'[rR]?"[^\n"\\]*(?:\\.[^\n"\\]*)*"')
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# Because of leftmost-then-longest match semantics, be sure to put the
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# longest operators first (e.g., if = came before ==, == would get
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# recognized as two instances of =).
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Operator = group(r"\*\*=?", r">>=?", r"<<=?", r"<>", r"!=",
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r"[+\-*/%&|^=<>]=?",
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r"~")
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Bracket = '[][(){}]'
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Special = group(r'\r?\n', r'[:;.,`]')
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Funny = group(Operator, Bracket, Special)
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PlainToken = group(Number, Funny, String, Name)
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Token = Ignore + PlainToken
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# First (or only) line of ' or " string.
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ContStr = group(r"[rR]?'[^\n'\\]*(?:\\.[^\n'\\]*)*" + group("'", r'\\\r?\n'),
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r'[rR]?"[^\n"\\]*(?:\\.[^\n"\\]*)*' + group('"', r'\\\r?\n'))
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PseudoExtras = group(r'\\\r?\n', Comment, Triple)
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PseudoToken = Whitespace + group(PseudoExtras, Number, Funny, ContStr, Name)
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tokenprog, pseudoprog, single3prog, double3prog = map(
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re.compile, (Token, PseudoToken, Single3, Double3))
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endprogs = {"'": re.compile(Single), '"': re.compile(Double),
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"'''": single3prog, '"""': double3prog,
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"r'''": single3prog, 'r"""': double3prog,
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"R'''": single3prog, 'R"""': double3prog, 'r': None, 'R': None}
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tabsize = 8
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class TokenError(Exception):
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pass
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def printtoken(type, token, (srow, scol), (erow, ecol), line): # for testing
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print "%d,%d-%d,%d:\t%s\t%s" % \
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(srow, scol, erow, ecol, tok_name[type], repr(token))
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def tokenize(readline, tokeneater=printtoken):
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lnum = parenlev = continued = 0
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namechars, numchars = string.letters + '_', string.digits
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contstr, needcont = '', 0
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contline = None
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indents = [0]
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while 1: # loop over lines in stream
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line = readline()
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lnum = lnum + 1
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pos, max = 0, len(line)
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if contstr: # continued string
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if not line:
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raise TokenError, ("EOF in multi-line string", strstart)
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endmatch = endprog.match(line)
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if endmatch:
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pos = end = endmatch.end(0)
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tokeneater(STRING, contstr + line[:end],
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strstart, (lnum, end), contline + line)
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contstr, needcont = '', 0
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contline = None
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elif needcont and line[-2:] != '\\\n' and line[-3:] != '\\\r\n':
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tokeneater(ERRORTOKEN, contstr + line,
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strstart, (lnum, len(line)), contline)
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contstr = ''
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contline = None
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continue
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else:
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contstr = contstr + line
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contline = contline + line
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continue
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elif parenlev == 0 and not continued: # new statement
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if not line: break
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column = 0
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while pos < max: # measure leading whitespace
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if line[pos] == ' ': column = column + 1
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elif line[pos] == '\t': column = (column/tabsize + 1)*tabsize
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elif line[pos] == '\f': column = 0
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else: break
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pos = pos + 1
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if pos == max: break
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if line[pos] in '#\r\n': # skip comments or blank lines
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tokeneater((NL, COMMENT)[line[pos] == '#'], line[pos:],
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(lnum, pos), (lnum, len(line)), line)
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continue
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if column > indents[-1]: # count indents or dedents
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indents.append(column)
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tokeneater(INDENT, line[:pos], (lnum, 0), (lnum, pos), line)
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while column < indents[-1]:
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indents = indents[:-1]
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tokeneater(DEDENT, '', (lnum, pos), (lnum, pos), line)
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else: # continued statement
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if not line:
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raise TokenError, ("EOF in multi-line statement", (lnum, 0))
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continued = 0
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while pos < max:
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pseudomatch = pseudoprog.match(line, pos)
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if pseudomatch: # scan for tokens
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start, end = pseudomatch.span(1)
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spos, epos, pos = (lnum, start), (lnum, end), end
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token, initial = line[start:end], line[start]
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if initial in numchars \
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or (initial == '.' and token != '.'): # ordinary number
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tokeneater(NUMBER, token, spos, epos, line)
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elif initial in '\r\n':
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tokeneater(parenlev > 0 and NL or NEWLINE,
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token, spos, epos, line)
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elif initial == '#':
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tokeneater(COMMENT, token, spos, epos, line)
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elif token in ("'''", '"""', # triple-quoted
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"r'''", 'r"""', "R'''", 'R"""'):
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endprog = endprogs[token]
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endmatch = endprog.match(line, pos)
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if endmatch: # all on one line
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pos = endmatch.end(0)
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token = line[start:pos]
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tokeneater(STRING, token, spos, (lnum, pos), line)
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else:
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strstart = (lnum, start) # multiple lines
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contstr = line[start:]
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contline = line
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break
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elif initial in ("'", '"') or \
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token[:2] in ("r'", 'r"', "R'", 'R"'):
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if token[-1] == '\n': # continued string
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strstart = (lnum, start)
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endprog = endprogs[initial] or endprogs[token[1]]
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contstr, needcont = line[start:], 1
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contline = line
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break
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else: # ordinary string
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tokeneater(STRING, token, spos, epos, line)
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elif initial in namechars: # ordinary name
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tokeneater(NAME, token, spos, epos, line)
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elif initial == '\\': # continued stmt
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continued = 1
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else:
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if initial in '([{': parenlev = parenlev + 1
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elif initial in ')]}': parenlev = parenlev - 1
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tokeneater(OP, token, spos, epos, line)
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else:
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tokeneater(ERRORTOKEN, line[pos],
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(lnum, pos), (lnum, pos+1), line)
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pos = pos + 1
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for indent in indents[1:]: # pop remaining indent levels
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tokeneater(DEDENT, '', (lnum, 0), (lnum, 0), '')
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tokeneater(ENDMARKER, '', (lnum, 0), (lnum, 0), '')
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if __name__ == '__main__': # testing
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import sys
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if len(sys.argv) > 1: tokenize(open(sys.argv[1]).readline)
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else: tokenize(sys.stdin.readline)
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