📁 //snap/core20/current/lib/python3.8/lib2to3/pygram.py
# Copyright 2006 Google, Inc. All Rights Reserved.
# Licensed to PSF under a Contributor Agreement.
"""Export the Python grammar and symbols."""
# Python imports
import os
# Local imports
from .pgen2 import token
from .pgen2 import driver
from . import pytree
# The grammar file
_GRAMMAR_FILE = os.path.join(os.path.dirname(__file__), "Grammar.txt")
_PATTERN_GRAMMAR_FILE = os.path.join(os.path.dirname(__file__),
"PatternGrammar.txt")
class Symbols(object):
def __init__(self, grammar):
"""Initializer.
Creates an attribute for each grammar symbol (nonterminal),
whose value is the symbol's type (an int >= 256).
"""
for name, symbol in grammar.symbol2number.items():
setattr(self, name, symbol)
python_grammar = driver.load_packaged_grammar("lib2to3", _GRAMMAR_FILE)
python_symbols = Symbols(python_grammar)
python_grammar_no_print_statement = python_grammar.copy()
del python_grammar_no_print_statement.keywords["print"]
python_grammar_no_print_and_exec_statement = python_grammar_no_print_statement.copy()
del python_grammar_no_print_and_exec_statement.keywords["exec"]
pattern_grammar = driver.load_packaged_grammar("lib2to3", _PATTERN_GRAMMAR_FILE)
pattern_symbols = Symbols(pattern_grammar)