mirror of
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7d2c39752f
As argparse now detects by default when the code was run as a module.
This leads to using the actual executable name instead of simply "python"
to display in the usage message ("usage: python -m ...").
585 lines
21 KiB
Python
585 lines
21 KiB
Python
"""Tokenization help for Python programs.
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tokenize(readline) is a generator that breaks a stream of bytes into
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Python tokens. It decodes the bytes according to PEP-0263 for
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determining source file encoding.
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It accepts a readline-like method which is called repeatedly to get the
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next line of input (or b"" for EOF). It generates 5-tuples with these
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members:
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the token type (see token.py)
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the token (a string)
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the starting (row, column) indices of the token (a 2-tuple of ints)
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the ending (row, column) indices of the token (a 2-tuple of ints)
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the original line (string)
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It is designed to match the working of the Python tokenizer exactly, except
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that it produces COMMENT tokens for comments and gives type OP for all
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operators. Additionally, all token lists start with an ENCODING token
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which tells you which encoding was used to decode the bytes stream.
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"""
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__author__ = 'Ka-Ping Yee <ping@lfw.org>'
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__credits__ = ('GvR, ESR, Tim Peters, Thomas Wouters, Fred Drake, '
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'Skip Montanaro, Raymond Hettinger, Trent Nelson, '
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'Michael Foord')
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from builtins import open as _builtin_open
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from codecs import lookup, BOM_UTF8
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import collections
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import functools
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from io import TextIOWrapper
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import itertools as _itertools
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import re
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import sys
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from token import *
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from token import EXACT_TOKEN_TYPES
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import _tokenize
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cookie_re = re.compile(r'^[ \t\f]*#.*?coding[:=][ \t]*([-\w.]+)', re.ASCII)
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blank_re = re.compile(br'^[ \t\f]*(?:[#\r\n]|$)', re.ASCII)
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import token
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__all__ = token.__all__ + ["tokenize", "generate_tokens", "detect_encoding",
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"untokenize", "TokenInfo", "open", "TokenError"]
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del token
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class TokenInfo(collections.namedtuple('TokenInfo', 'type string start end line')):
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def __repr__(self):
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annotated_type = '%d (%s)' % (self.type, tok_name[self.type])
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return ('TokenInfo(type=%s, string=%r, start=%r, end=%r, line=%r)' %
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self._replace(type=annotated_type))
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@property
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def exact_type(self):
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if self.type == OP and self.string in EXACT_TOKEN_TYPES:
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return EXACT_TOKEN_TYPES[self.string]
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else:
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return self.type
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def group(*choices): return '(' + '|'.join(choices) + ')'
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def any(*choices): return group(*choices) + '*'
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def maybe(*choices): return group(*choices) + '?'
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# Note: we use unicode matching for names ("\w") but ascii matching for
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# number literals.
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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'\w+'
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Hexnumber = r'0[xX](?:_?[0-9a-fA-F])+'
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Binnumber = r'0[bB](?:_?[01])+'
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Octnumber = r'0[oO](?:_?[0-7])+'
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Decnumber = r'(?:0(?:_?0)*|[1-9](?:_?[0-9])*)'
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Intnumber = group(Hexnumber, Binnumber, Octnumber, Decnumber)
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Exponent = r'[eE][-+]?[0-9](?:_?[0-9])*'
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Pointfloat = group(r'[0-9](?:_?[0-9])*\.(?:[0-9](?:_?[0-9])*)?',
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r'\.[0-9](?:_?[0-9])*') + maybe(Exponent)
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Expfloat = r'[0-9](?:_?[0-9])*' + Exponent
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Floatnumber = group(Pointfloat, Expfloat)
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Imagnumber = group(r'[0-9](?:_?[0-9])*[jJ]', Floatnumber + r'[jJ]')
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Number = group(Imagnumber, Floatnumber, Intnumber)
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# Return the empty string, plus all of the valid string prefixes.
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def _all_string_prefixes():
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# The valid string prefixes. Only contain the lower case versions,
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# and don't contain any permutations (include 'fr', but not
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# 'rf'). The various permutations will be generated.
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_valid_string_prefixes = ['b', 'r', 'u', 'f', 'br', 'fr']
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# if we add binary f-strings, add: ['fb', 'fbr']
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result = {''}
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for prefix in _valid_string_prefixes:
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for t in _itertools.permutations(prefix):
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# create a list with upper and lower versions of each
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# character
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for u in _itertools.product(*[(c, c.upper()) for c in t]):
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result.add(''.join(u))
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return result
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@functools.lru_cache
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def _compile(expr):
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return re.compile(expr, re.UNICODE)
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# Note that since _all_string_prefixes includes the empty string,
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# StringPrefix can be the empty string (making it optional).
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StringPrefix = group(*_all_string_prefixes())
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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(StringPrefix + "'''", StringPrefix + '"""')
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# Single-line ' or " string.
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String = group(StringPrefix + r"'[^\n'\\]*(?:\\.[^\n'\\]*)*'",
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StringPrefix + r'"[^\n"\\]*(?:\\.[^\n"\\]*)*"')
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# Sorting in reverse order puts the long operators before their prefixes.
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# Otherwise if = came before ==, == would get recognized as two instances
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# of =.
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Special = group(*map(re.escape, sorted(EXACT_TOKEN_TYPES, reverse=True)))
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Funny = group(r'\r?\n', 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(StringPrefix + r"'[^\n'\\]*(?:\\.[^\n'\\]*)*" +
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group("'", r'\\\r?\n'),
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StringPrefix + r'"[^\n"\\]*(?:\\.[^\n"\\]*)*' +
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group('"', r'\\\r?\n'))
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PseudoExtras = group(r'\\\r?\n|\Z', Comment, Triple)
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PseudoToken = Whitespace + group(PseudoExtras, Number, Funny, ContStr, Name)
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# For a given string prefix plus quotes, endpats maps it to a regex
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# to match the remainder of that string. _prefix can be empty, for
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# a normal single or triple quoted string (with no prefix).
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endpats = {}
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for _prefix in _all_string_prefixes():
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endpats[_prefix + "'"] = Single
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endpats[_prefix + '"'] = Double
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endpats[_prefix + "'''"] = Single3
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endpats[_prefix + '"""'] = Double3
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del _prefix
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# A set of all of the single and triple quoted string prefixes,
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# including the opening quotes.
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single_quoted = set()
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triple_quoted = set()
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for t in _all_string_prefixes():
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for u in (t + '"', t + "'"):
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single_quoted.add(u)
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for u in (t + '"""', t + "'''"):
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triple_quoted.add(u)
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del t, u
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tabsize = 8
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class TokenError(Exception): pass
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class Untokenizer:
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def __init__(self):
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self.tokens = []
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self.prev_row = 1
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self.prev_col = 0
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self.prev_type = None
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self.encoding = None
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def add_whitespace(self, start):
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row, col = start
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if row < self.prev_row or row == self.prev_row and col < self.prev_col:
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raise ValueError("start ({},{}) precedes previous end ({},{})"
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.format(row, col, self.prev_row, self.prev_col))
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row_offset = row - self.prev_row
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if row_offset:
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self.tokens.append("\\\n" * row_offset)
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self.prev_col = 0
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col_offset = col - self.prev_col
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if col_offset:
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self.tokens.append(" " * col_offset)
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def escape_brackets(self, token):
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characters = []
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consume_until_next_bracket = False
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for character in token:
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if character == "}":
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if consume_until_next_bracket:
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consume_until_next_bracket = False
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else:
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characters.append(character)
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if character == "{":
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n_backslashes = sum(
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1 for char in _itertools.takewhile(
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"\\".__eq__,
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characters[-2::-1]
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)
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)
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if n_backslashes % 2 == 0 or characters[-1] != "N":
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characters.append(character)
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else:
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consume_until_next_bracket = True
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characters.append(character)
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return "".join(characters)
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def untokenize(self, iterable):
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it = iter(iterable)
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indents = []
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startline = False
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for t in it:
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if len(t) == 2:
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self.compat(t, it)
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break
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tok_type, token, start, end, line = t
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if tok_type == ENCODING:
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self.encoding = token
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continue
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if tok_type == ENDMARKER:
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break
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if tok_type == INDENT:
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indents.append(token)
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continue
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elif tok_type == DEDENT:
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indents.pop()
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self.prev_row, self.prev_col = end
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continue
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elif tok_type in (NEWLINE, NL):
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startline = True
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elif startline and indents:
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indent = indents[-1]
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if start[1] >= len(indent):
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self.tokens.append(indent)
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self.prev_col = len(indent)
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startline = False
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elif tok_type == FSTRING_MIDDLE:
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if '{' in token or '}' in token:
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token = self.escape_brackets(token)
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last_line = token.splitlines()[-1]
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end_line, end_col = end
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extra_chars = last_line.count("{{") + last_line.count("}}")
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end = (end_line, end_col + extra_chars)
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elif tok_type in (STRING, FSTRING_START) and self.prev_type in (STRING, FSTRING_END):
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self.tokens.append(" ")
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self.add_whitespace(start)
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self.tokens.append(token)
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self.prev_row, self.prev_col = end
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if tok_type in (NEWLINE, NL):
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self.prev_row += 1
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self.prev_col = 0
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self.prev_type = tok_type
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return "".join(self.tokens)
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def compat(self, token, iterable):
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indents = []
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toks_append = self.tokens.append
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startline = token[0] in (NEWLINE, NL)
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prevstring = False
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in_fstring = 0
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for tok in _itertools.chain([token], iterable):
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toknum, tokval = tok[:2]
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if toknum == ENCODING:
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self.encoding = tokval
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continue
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if toknum in (NAME, NUMBER):
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tokval += ' '
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# Insert a space between two consecutive strings
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if toknum == STRING:
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if prevstring:
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tokval = ' ' + tokval
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prevstring = True
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else:
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prevstring = False
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if toknum == FSTRING_START:
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in_fstring += 1
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elif toknum == FSTRING_END:
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in_fstring -= 1
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if toknum == INDENT:
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indents.append(tokval)
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continue
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elif toknum == DEDENT:
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indents.pop()
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continue
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elif toknum in (NEWLINE, NL):
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startline = True
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elif startline and indents:
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toks_append(indents[-1])
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startline = False
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elif toknum == FSTRING_MIDDLE:
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tokval = self.escape_brackets(tokval)
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# Insert a space between two consecutive brackets if we are in an f-string
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if tokval in {"{", "}"} and self.tokens and self.tokens[-1] == tokval and in_fstring:
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tokval = ' ' + tokval
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# Insert a space between two consecutive f-strings
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if toknum in (STRING, FSTRING_START) and self.prev_type in (STRING, FSTRING_END):
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self.tokens.append(" ")
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toks_append(tokval)
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self.prev_type = toknum
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def untokenize(iterable):
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"""Transform tokens back into Python source code.
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It returns a bytes object, encoded using the ENCODING
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token, which is the first token sequence output by tokenize.
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Each element returned by the iterable must be a token sequence
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with at least two elements, a token number and token value. If
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only two tokens are passed, the resulting output is poor.
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Round-trip invariant for full input:
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Untokenized source will match input source exactly
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Round-trip invariant for limited input:
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# Output bytes will tokenize back to the input
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t1 = [tok[:2] for tok in tokenize(f.readline)]
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newcode = untokenize(t1)
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readline = BytesIO(newcode).readline
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t2 = [tok[:2] for tok in tokenize(readline)]
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assert t1 == t2
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"""
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ut = Untokenizer()
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out = ut.untokenize(iterable)
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if ut.encoding is not None:
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out = out.encode(ut.encoding)
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return out
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def _get_normal_name(orig_enc):
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"""Imitates get_normal_name in Parser/tokenizer/helpers.c."""
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# Only care about the first 12 characters.
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enc = orig_enc[:12].lower().replace("_", "-")
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if enc == "utf-8" or enc.startswith("utf-8-"):
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return "utf-8"
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if enc in ("latin-1", "iso-8859-1", "iso-latin-1") or \
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enc.startswith(("latin-1-", "iso-8859-1-", "iso-latin-1-")):
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return "iso-8859-1"
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return orig_enc
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def detect_encoding(readline):
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"""
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The detect_encoding() function is used to detect the encoding that should
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be used to decode a Python source file. It requires one argument, readline,
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in the same way as the tokenize() generator.
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It will call readline a maximum of twice, and return the encoding used
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(as a string) and a list of any lines (left as bytes) it has read in.
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It detects the encoding from the presence of a utf-8 bom or an encoding
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cookie as specified in pep-0263. If both a bom and a cookie are present,
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but disagree, a SyntaxError will be raised. If the encoding cookie is an
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invalid charset, raise a SyntaxError. Note that if a utf-8 bom is found,
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'utf-8-sig' is returned.
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If no encoding is specified, then the default of 'utf-8' will be returned.
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"""
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try:
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filename = readline.__self__.name
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except AttributeError:
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filename = None
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bom_found = False
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encoding = None
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default = 'utf-8'
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def read_or_stop():
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try:
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return readline()
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except StopIteration:
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return b''
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def find_cookie(line):
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try:
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# Decode as UTF-8. Either the line is an encoding declaration,
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# in which case it should be pure ASCII, or it must be UTF-8
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# per default encoding.
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line_string = line.decode('utf-8')
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except UnicodeDecodeError:
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msg = "invalid or missing encoding declaration"
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if filename is not None:
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msg = '{} for {!r}'.format(msg, filename)
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raise SyntaxError(msg)
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match = cookie_re.match(line_string)
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if not match:
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return None
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encoding = _get_normal_name(match.group(1))
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try:
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codec = lookup(encoding)
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except LookupError:
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# This behaviour mimics the Python interpreter
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if filename is None:
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msg = "unknown encoding: " + encoding
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else:
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msg = "unknown encoding for {!r}: {}".format(filename,
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encoding)
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raise SyntaxError(msg)
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if bom_found:
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if encoding != 'utf-8':
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# This behaviour mimics the Python interpreter
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if filename is None:
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msg = 'encoding problem: utf-8'
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else:
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msg = 'encoding problem for {!r}: utf-8'.format(filename)
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raise SyntaxError(msg)
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encoding += '-sig'
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return encoding
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first = read_or_stop()
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if first.startswith(BOM_UTF8):
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bom_found = True
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first = first[3:]
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default = 'utf-8-sig'
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if not first:
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return default, []
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encoding = find_cookie(first)
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if encoding:
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return encoding, [first]
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if not blank_re.match(first):
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return default, [first]
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second = read_or_stop()
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if not second:
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return default, [first]
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encoding = find_cookie(second)
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if encoding:
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return encoding, [first, second]
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return default, [first, second]
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def open(filename):
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"""Open a file in read only mode using the encoding detected by
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detect_encoding().
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"""
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buffer = _builtin_open(filename, 'rb')
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try:
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encoding, lines = detect_encoding(buffer.readline)
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buffer.seek(0)
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text = TextIOWrapper(buffer, encoding, line_buffering=True)
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text.mode = 'r'
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return text
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except:
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buffer.close()
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raise
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def tokenize(readline):
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"""
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The tokenize() generator requires one argument, readline, which
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must be a callable object which provides the same interface as the
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readline() method of built-in file objects. Each call to the function
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should return one line of input as bytes. Alternatively, readline
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can be a callable function terminating with StopIteration:
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readline = open(myfile, 'rb').__next__ # Example of alternate readline
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The generator produces 5-tuples with these members: the token type; the
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token string; a 2-tuple (srow, scol) of ints specifying the row and
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column where the token begins in the source; a 2-tuple (erow, ecol) of
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ints specifying the row and column where the token ends in the source;
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and the line on which the token was found. The line passed is the
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physical line.
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The first token sequence will always be an ENCODING token
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which tells you which encoding was used to decode the bytes stream.
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"""
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encoding, consumed = detect_encoding(readline)
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rl_gen = _itertools.chain(consumed, iter(readline, b""))
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if encoding is not None:
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if encoding == "utf-8-sig":
|
|
# BOM will already have been stripped.
|
|
encoding = "utf-8"
|
|
yield TokenInfo(ENCODING, encoding, (0, 0), (0, 0), '')
|
|
yield from _generate_tokens_from_c_tokenizer(rl_gen.__next__, encoding, extra_tokens=True)
|
|
|
|
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 _generate_tokens_from_c_tokenizer(readline, extra_tokens=True)
|
|
|
|
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()
|
|
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 = _generate_tokens_from_c_tokenizer(
|
|
sys.stdin.readline, extra_tokens=True)
|
|
|
|
|
|
# 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
|
|
|
|
def _transform_msg(msg):
|
|
"""Transform error messages from the C tokenizer into the Python tokenize
|
|
|
|
The C tokenizer is more picky than the Python one, so we need to massage
|
|
the error messages a bit for backwards compatibility.
|
|
"""
|
|
if "unterminated triple-quoted string literal" in msg:
|
|
return "EOF in multi-line string"
|
|
return msg
|
|
|
|
def _generate_tokens_from_c_tokenizer(source, encoding=None, extra_tokens=False):
|
|
"""Tokenize a source reading Python code as unicode strings using the internal C tokenizer"""
|
|
if encoding is None:
|
|
it = _tokenize.TokenizerIter(source, extra_tokens=extra_tokens)
|
|
else:
|
|
it = _tokenize.TokenizerIter(source, encoding=encoding, extra_tokens=extra_tokens)
|
|
try:
|
|
for info in it:
|
|
yield TokenInfo._make(info)
|
|
except SyntaxError as e:
|
|
if type(e) != SyntaxError:
|
|
raise e from None
|
|
msg = _transform_msg(e.msg)
|
|
raise TokenError(msg, (e.lineno, e.offset)) from None
|
|
|
|
|
|
if __name__ == "__main__":
|
|
main()
|