Python学习入门代码.zip

"""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 <[email protected]>' __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__ + ["COMMENT", "tokenize", "detect_encoding", "NL", "untokenize", "ENCODING", "TokenInfo"] 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 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, '@': 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 permuations (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 = set(['']) 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: