# Copyright (c) 2015, 2016 Rocky Bernstein # Copyright (c) 2005 by Dan Pascu # Copyright (c) 2000-2002 by hartmut Goebel # Copyright (c) 1999 John Aycock # # See LICENSE for license """ A spark grammar for Python 3.x. However instead of terminal symbols being the usual ASCII text, e.g. 5, myvariable, "for", etc. they are CPython Bytecode tokens, e.g. "LOAD_CONST 5", "STORE NAME myvariable", "SETUP_LOOP", etc. If we succeed in creating a parse tree, then we have a Python program that a later phase can tern into a sequence of ASCII text. """ from __future__ import print_function from uncompyle6.parser import PythonParser, PythonParserSingle, nop_func from uncompyle6.parsers.astnode import AST from spark_parser import DEFAULT_DEBUG as PARSER_DEFAULT_DEBUG from uncompyle6 import PYTHON3 class Python3Parser(PythonParser): def __init__(self, debug_parser=PARSER_DEFAULT_DEBUG): self.added_rules = set() if PYTHON3: super().__init__(AST, 'stmts', debug=debug_parser) else: super(Python3Parser, self).__init__(AST, 'stmts', debug=debug_parser) self.new_rules = set() def add_unique_rule(self, rule, opname, count, customize): """Add rule to grammar, but only if it hasn't been added previously """ if rule not in self.new_rules: # print("XXX ", rule) # debug self.new_rules.add(rule) self.addRule(rule, nop_func) customize[opname] = count pass return def p_list_comprehension3(self, args): """ # Python3 scanner adds LOAD_LISTCOMP. Python3 does list comprehension like # other comprehensions (set, dictionary). # listcomp is a custom Python3 rule expr ::= listcomp list_for ::= expr FOR_ITER designator list_iter JUMP_BACK # See also common Python p_list_comprehension """ def p_dictcomp3(self, args): """" dictcomp ::= LOAD_DICTCOMP LOAD_CONST MAKE_FUNCTION_0 expr GET_ITER CALL_FUNCTION_1 """ def p_grammar(self, args): ''' sstmt ::= stmt sstmt ::= ifelsestmtr sstmt ::= return_stmt RETURN_LAST stmts_opt ::= stmts stmts_opt ::= passstmt passstmt ::= _stmts ::= _stmts stmt _stmts ::= stmt # statements with continue c_stmts ::= _stmts c_stmts ::= _stmts lastc_stmt c_stmts ::= lastc_stmt c_stmts ::= continue_stmts lastc_stmt ::= iflaststmt lastc_stmt ::= whileelselaststmt lastc_stmt ::= forelselaststmt lastc_stmt ::= ifelsestmtr lastc_stmt ::= ifelsestmtc lastc_stmt ::= tryelsestmtc c_stmts_opt ::= c_stmts c_stmts_opt ::= passstmt l_stmts ::= _stmts l_stmts ::= return_stmts l_stmts ::= continue_stmts l_stmts ::= _stmts lastl_stmt l_stmts ::= lastl_stmt lastl_stmt ::= iflaststmtl lastl_stmt ::= ifelsestmtl lastl_stmt ::= forelselaststmtl lastl_stmt ::= tryelsestmtl l_stmts_opt ::= l_stmts l_stmts_opt ::= passstmt suite_stmts ::= _stmts suite_stmts ::= return_stmts suite_stmts ::= continue_stmts suite_stmts_opt ::= suite_stmts suite_stmts_opt ::= passstmt else_suite ::= suite_stmts else_suitel ::= l_stmts else_suitec ::= c_stmts else_suitec ::= return_stmts stmt ::= classdef stmt ::= call_stmt stmt ::= return_stmt return_stmt ::= ret_expr RETURN_VALUE return_stmts ::= return_stmt return_stmts ::= _stmts return_stmt return_if_stmts ::= return_if_stmt come_from_opt return_if_stmts ::= _stmts return_if_stmt return_if_stmt ::= ret_expr RETURN_VALUE stmt ::= break_stmt break_stmt ::= BREAK_LOOP stmt ::= continue_stmt continue_stmt ::= CONTINUE continue_stmt ::= CONTINUE_LOOP continue_stmts ::= _stmts lastl_stmt continue_stmt continue_stmts ::= lastl_stmt continue_stmt continue_stmts ::= continue_stmt stmt ::= raise_stmt0 stmt ::= raise_stmt1 stmt ::= raise_stmt2 stmt ::= raise_stmt3 raise_stmt0 ::= RAISE_VARARGS_0 raise_stmt1 ::= expr RAISE_VARARGS_1 raise_stmt2 ::= expr expr RAISE_VARARGS_2 raise_stmt3 ::= expr expr expr RAISE_VARARGS_3 stmt ::= exec_stmt exec_stmt ::= expr exprlist DUP_TOP EXEC_STMT exec_stmt ::= expr exprlist EXEC_STMT stmt ::= assert stmt ::= assert2 stmt ::= ifstmt stmt ::= ifelsestmt stmt ::= whilestmt stmt ::= while1stmt stmt ::= whileelsestmt stmt ::= while1elsestmt stmt ::= forstmt stmt ::= forelsestmt stmt ::= trystmt stmt ::= tryelsestmt stmt ::= tryfinallystmt stmt ::= withstmt stmt ::= withasstmt stmt ::= del_stmt del_stmt ::= DELETE_FAST del_stmt ::= DELETE_NAME del_stmt ::= DELETE_GLOBAL del_stmt ::= expr DELETE_SLICE+0 del_stmt ::= expr expr DELETE_SLICE+1 del_stmt ::= expr expr DELETE_SLICE+2 del_stmt ::= expr expr expr DELETE_SLICE+3 del_stmt ::= delete_subscr delete_subscr ::= expr expr DELETE_SUBSCR del_stmt ::= expr DELETE_ATTR kwarg ::= LOAD_CONST expr kwargs ::= kwargs kwarg kwargs ::= classdef ::= build_class designator # Python3 introduced LOAD_BUILD_CLASS # the definition of build_class is a custom rule stmt ::= classdefdeco classdefdeco ::= classdefdeco1 designator classdefdeco1 ::= expr classdefdeco1 CALL_FUNCTION_1 classdefdeco1 ::= expr classdefdeco2 CALL_FUNCTION_1 classdefdeco2 ::= LOAD_CONST expr mkfunc CALL_FUNCTION_0 BUILD_CLASS assert ::= assert_expr jmp_true LOAD_ASSERT RAISE_VARARGS_1 assert2 ::= assert_expr jmp_true LOAD_ASSERT expr CALL_FUNCTION_1 RAISE_VARARGS_1 assert2 ::= assert_expr jmp_true LOAD_ASSERT expr RAISE_VARARGS_2 assert_expr ::= expr assert_expr ::= assert_expr_or assert_expr ::= assert_expr_and assert_expr_or ::= assert_expr jmp_true expr assert_expr_and ::= assert_expr jmp_false expr ifstmt ::= testexpr _ifstmts_jump testexpr ::= testfalse testexpr ::= testtrue testfalse ::= expr jmp_false testtrue ::= expr jmp_true _ifstmts_jump ::= return_if_stmts _ifstmts_jump ::= c_stmts_opt JUMP_FORWARD COME_FROM iflaststmt ::= testexpr c_stmts_opt JUMP_ABSOLUTE iflaststmtl ::= testexpr c_stmts_opt JUMP_BACK ifelsestmt ::= testexpr c_stmts_opt JUMP_FORWARD else_suite COME_FROM ifelsestmtc ::= testexpr c_stmts_opt JUMP_ABSOLUTE else_suitec ifelsestmtr ::= testexpr return_if_stmts return_stmts ifelsestmtl ::= testexpr c_stmts_opt JUMP_BACK else_suitel # FIXME: this feels like a hack. Is it just 1 or two # COME_FROMs? the parsed tree for this and even with just the # one COME_FROM for Python 2.7 seems to associate the # COME_FROM targets from the wrong places trystmt ::= SETUP_EXCEPT suite_stmts_opt POP_BLOCK try_middle _come_from # this is nested inside a trystmt tryfinallystmt ::= SETUP_FINALLY suite_stmts_opt POP_BLOCK LOAD_CONST COME_FROM suite_stmts_opt END_FINALLY tryelsestmt ::= SETUP_EXCEPT suite_stmts_opt POP_BLOCK try_middle else_suite come_froms tryelsestmtc ::= SETUP_EXCEPT suite_stmts_opt POP_BLOCK try_middle else_suitec COME_FROM tryelsestmtl ::= SETUP_EXCEPT suite_stmts_opt POP_BLOCK try_middle else_suitel COME_FROM try_middle ::= jmp_abs COME_FROM except_stmts END_FINALLY try_middle ::= JUMP_FORWARD COME_FROM except_stmts END_FINALLY COME_FROM except_stmts ::= except_stmts except_stmt except_stmts ::= except_stmt except_stmt ::= except_cond1 except_suite except_stmt ::= except_cond2 except_suite except_stmt ::= except_cond2 except_suite_finalize except_stmt ::= except except_stmt ::= except_pop_except # Python3 introduced POP_EXCEPT except_suite ::= c_stmts_opt POP_EXCEPT jump_except jump_except ::= JUMP_ABSOLUTE jump_except ::= JUMP_BACK jump_except ::= JUMP_FORWARD jump_except ::= CONTINUE # This is used in Python 3 in # "except ... as e" to remove 'e' after the c_stmts_opt finishes except_suite_finalize ::= SETUP_FINALLY c_stmts_opt except_var_finalize END_FINALLY _jump except_var_finalize ::= POP_BLOCK POP_EXCEPT LOAD_CONST COME_FROM LOAD_CONST designator del_stmt except_suite ::= return_stmts except_cond1 ::= DUP_TOP expr COMPARE_OP jmp_false POP_TOP POP_TOP POP_TOP except_cond2 ::= DUP_TOP expr COMPARE_OP jmp_false POP_TOP designator POP_TOP except ::= POP_TOP POP_TOP POP_TOP c_stmts_opt POP_EXCEPT _jump except ::= POP_TOP POP_TOP POP_TOP return_stmts jmp_abs ::= JUMP_ABSOLUTE jmp_abs ::= JUMP_BACK withstmt ::= expr SETUP_WITH POP_TOP suite_stmts_opt POP_BLOCK LOAD_CONST COME_FROM WITH_CLEANUP END_FINALLY withasstmt ::= expr SETUP_WITH designator suite_stmts_opt POP_BLOCK LOAD_CONST COME_FROM WITH_CLEANUP END_FINALLY ''' def p_misc(self, args): """ try_middle ::= JUMP_FORWARD COME_FROM except_stmts END_FINALLY NOP COME_FROM """ def p_jump3(self, args): """ come_froms ::= come_froms COME_FROM come_froms ::= COME_FROM """ def p_stmt3(self, args): """ stmt ::= LOAD_CLOSURE RETURN_VALUE RETURN_LAST stmt ::= whileTruestmt ifelsestmt ::= testexpr c_stmts_opt JUMP_FORWARD else_suite _come_from forstmt ::= SETUP_LOOP expr _for designator for_block POP_BLOCK NOP _come_from whileTruestmt ::= SETUP_LOOP l_stmts_opt JUMP_BACK POP_BLOCK _come_from whileTruestmt ::= SETUP_LOOP l_stmts_opt JUMP_BACK POP_BLOCK NOP _come_from # Python < 3.5 no POP BLOCK whileTruestmt ::= SETUP_LOOP l_stmts_opt JUMP_BACK _come_from whileTruestmt ::= SETUP_LOOP l_stmts_opt JUMP_BACK NOP _come_from """ def p_genexpr3(self, args): ''' load_genexpr ::= LOAD_GENEXPR load_genexpr ::= BUILD_TUPLE_1 LOAD_GENEXPR LOAD_CONST # Is there something general going on here? genexpr ::= LOAD_GENEXPR LOAD_CONST MAKE_FUNCTION_0 expr GET_ITER CALL_FUNCTION_1 genexpr ::= load_closure LOAD_GENEXPR LOAD_CONST MAKE_CLOSURE_0 expr GET_ITER CALL_FUNCTION_1 dictcomp ::= load_closure LOAD_DICTCOMP LOAD_CONST MAKE_CLOSURE_0 expr GET_ITER CALL_FUNCTION_1 ''' def p_expr3(self, args): ''' expr ::= LOAD_CLASSNAME expr ::= LOAD_ASSERT # Python3 drops slice0..slice3 # Python 3.3+ adds yield from expr ::= yield_from yield_from ::= expr expr YIELD_FROM # In Python 2, DUP_TOP_TWO is DUP_TOPX_2 binary_subscr2 ::= expr expr DUP_TOP_TWO BINARY_SUBSCR ''' @staticmethod def call_fn_name(token): """Customize CALL_FUNCTION to add the number of positional arguments""" return '%s_%i' % (token.type, token.attr) def custom_build_class_rule(self, opname, i, token, tokens, customize): ''' # Should the first rule be somehow folded into the 2nd one? build_class ::= LOAD_BUILD_CLASS mkfunc LOAD_CLASSNAME {expr}^n CALL_FUNCTION_n+2 LOAD_CONST CALL_FUNCTION_n build_class ::= LOAD_BUILD_CLASS mkfunc expr call_function CALL_FUNCTION_3 ''' # FIXME: I bet this can be simplified # look for next MAKE_FUNCTION for i in range(i+1, len(tokens)): if tokens[i].type.startswith('MAKE_FUNCTION'): break elif tokens[i].type.startswith('MAKE_CLOSURE'): break pass assert i < len(tokens), "build_class needs to find MAKE_FUNCTION" assert tokens[i+1].type == 'LOAD_CONST', \ "build_class expecting CONST after MAKE_FUNCTION" for i in range(i, len(tokens)): if tokens[i].type == 'CALL_FUNCTION': call_fn_tok = tokens[i] break assert call_fn_tok, "build_class custom rule needs to find CALL_FUNCTION" # customize build_class rule call_function = self.call_fn_name(call_fn_tok) args_pos = call_fn_tok.attr & 0xff args_kw = (call_fn_tok.attr >> 8) & 0xff rule = ("build_class ::= LOAD_BUILD_CLASS mkfunc %s" "%s" % (('expr ' * (args_pos - 1) + ('kwarg ' * args_kw)), call_function)) self.add_unique_rule(rule, opname, token.attr, customize) # Can the above build_class rule be folded into this rule? rule = ("build_class ::= LOAD_BUILD_CLASS mkfunc expr call_function " "CALL_FUNCTION_" + str(args_pos+1)) self.add_unique_rule(rule, opname, token.attr, customize) return def custom_classfunc_rule(self, opname, token, customize): """ call_function ::= expr {expr}^n CALL_FUNCTION_n call_function ::= expr {expr}^n CALL_FUNCTION_VAR_n POP_TOP call_function ::= expr {expr}^n CALL_FUNCTION_VAR_KW_n POP_TOP call_function ::= expr {expr}^n CALL_FUNCTION_KW_n POP_TOP """ # Low byte indicates number of positional paramters, # high byte number of positional parameters args_pos = token.attr & 0xff args_kw = (token.attr >> 8) & 0xff nak = ( len(opname)-len('CALL_FUNCTION') ) // 3 token.type = self.call_fn_name(token) rule = ('call_function ::= expr ' + ('pos_arg ' * args_pos) + ('kwarg ' * args_kw) + 'expr ' * nak + token.type) self.add_unique_rule(rule, token.type, args_pos, customize) def add_custom_rules(self, tokens, customize): """ Special handling for opcodes that take a variable number of arguments -- we add a new rule for each: unpack_list ::= UNPACK_LIST_n {expr}^n unpack ::= UNPACK_TUPLE_n {expr}^n unpack ::= UNPACK_SEQEUENCE_n {expr}^n unpack_ex ::= UNPACK_EX_b_a {expr}^(a+b) mkfunc ::= {pos_arg}^n LOAD_CONST MAKE_FUNCTION_n mklambda ::= {pos_arg}^n LOAD_LAMBDA MAKE_FUNCTION_n mkfunc ::= {pos_arg}^n load_closure LOAD_CONST MAKE_FUNCTION_n genexpr ::= {pos_arg}^n LOAD_GENEXPR MAKE_FUNCTION_n listcomp ::= load_closure expr GET_ITER CALL_FUNCTION_1 # build_class (see load_build_class) build_list ::= {expr}^n BUILD_LIST_n build_list ::= {expr}^n BUILD_TUPLE_n load_closure ::= {LOAD_CLOSURE}^n BUILD_TUPLE_n # call_function (see custom_classfunc_rule) Python 3.3+: listcomp ::= LOAD_LISTCOMP LOAD_CONST MAKE_FUNCTION_0 expr GET_ITER CALL_FUNCTION_1 listcomp ::= {expr}^n LOAD_LISTCOMP MAKE_CLOSURE GET_ITER CALL_FUNCTION_1 dictcomp ::= LOAD_DICTCOMP LOAD_CONST MAKE_FUNCTION_0 expr GET_ITER CALL_FUNCTION_1 Python < 3.3 listcomp ::= LOAD_LISTCOMP MAKE_FUNCTION_0 expr GET_ITER CALL_FUNCTION_1 setcomp ::= {expr}^n LOAD_SETCOMP MAKE_CLOSURE GET_ITER CALL_FUNCTION_1 """ for i, token in enumerate(tokens): opname = token.type opname_base = opname[:opname.rfind('_')] if opname in ('CALL_FUNCTION', 'CALL_FUNCTION_VAR', 'CALL_FUNCTION_VAR_KW', 'CALL_FUNCTION_KW'): self.custom_classfunc_rule(opname, token, customize) elif opname == 'LOAD_LISTCOMP': if self.version >= 3.3: rule = ("listcomp ::= LOAD_LISTCOMP LOAD_CONST MAKE_FUNCTION_0 expr " "GET_ITER CALL_FUNCTION_1") else: rule = ("listcomp ::= LOAD_LISTCOMP MAKE_FUNCTION_0 expr " "GET_ITER CALL_FUNCTION_1") self.add_unique_rule(rule, opname, token.attr, customize) elif opname == 'LOAD_DICTCOMP': if self.version >= 3.3: rule = ("dictcomp ::= LOAD_DICTCOMP LOAD_CONST MAKE_FUNCTION_0 expr " "GET_ITER CALL_FUNCTION_1") else: rule = ("dictcomp ::= LOAD_DICTCOMP MAKE_FUNCTION_0 expr " "GET_ITER CALL_FUNCTION_1") self.add_unique_rule(rule, opname, token.attr, customize) elif opname == 'LOAD_SETCOMP': if self.version >= 3.3: rule = ("setcomp ::= LOAD_SETCOMP LOAD_CONST MAKE_FUNCTION_0 expr " "GET_ITER CALL_FUNCTION_1") else: rule = ("setcomp ::= LOAD_SETCOMP MAKE_FUNCTION_0 expr " "GET_ITER CALL_FUNCTION_1") self.add_unique_rule(rule, opname, token.attr, customize) elif opname == 'LOAD_BUILD_CLASS': self.custom_build_class_rule(opname, i, token, tokens, customize) elif opname_base in ('BUILD_LIST', 'BUILD_TUPLE', 'BUILD_SET'): v = token.attr rule = ('build_list ::= ' + 'expr1024 ' * int(v//1024) + 'expr32 ' * int((v//32)%32) + 'expr '*(v%32) + opname) self.add_unique_rule(rule, opname, token.attr, customize) if opname_base == 'BUILD_TUPLE': rule = ('load_closure ::= %s%s' % (('LOAD_CLOSURE ' * v), opname)) self.add_unique_rule(rule, opname, token.attr, customize) elif opname_base == 'BUILD_MAP': kvlist_n = "kvlist_%s" % token.attr if self.version >= 3.5: rule = kvlist_n + ' ::= ' + 'expr ' * (token.attr*2) self.add_unique_rule(rule, opname, token.attr, customize) rule = "mapexpr ::= %s %s" % (kvlist_n, opname) else: rule = kvlist_n + ' ::= ' + 'expr expr STORE_MAP ' * token.attr self.add_unique_rule(rule, opname, token.attr, customize) rule = "mapexpr ::= %s %s" % (opname, kvlist_n) self.add_unique_rule(rule, opname, token.attr, customize) elif opname_base in ('UNPACK_EX'): before_count, after_count = token.attr rule = 'unpack ::= ' + opname + ' designator' * (before_count + after_count + 1) self.add_unique_rule(rule, opname, token.attr, customize) elif opname_base in ('UNPACK_TUPLE', 'UNPACK_SEQUENCE'): rule = 'unpack ::= ' + opname + ' designator' * token.attr self.add_unique_rule(rule, opname, token.attr, customize) elif opname_base == 'UNPACK_LIST': rule = 'unpack_list ::= ' + opname + ' designator' * token.attr elif opname_base.startswith('MAKE_FUNCTION'): args_pos, args_kw, annotate_args = token.attr rule = ('mklambda ::= %sLOAD_LAMBDA LOAD_CONST %s' % ('pos_arg '* args_pos, opname)) self.add_unique_rule(rule, opname, token.attr, customize) if self.version > 3.2: rule = ('mkfunc ::= %skwargs %s %s' % ('pos_arg ' * args_pos, 'LOAD_CONST ' * 2, opname)) else: rule = ('mkfunc ::= %sLOAD_CONST %s' % ('pos_arg ' * args_pos, opname)) self.add_unique_rule(rule, opname, token.attr, customize) elif opname.startswith('MAKE_CLOSURE'): self.add_unique_rule('mklambda ::= %sload_closure LOAD_LAMBDA LOAD_CONST %s' % ('pos_arg ' * token.attr, opname), opname, token.attr, customize) self.add_unique_rule('genexpr ::= %sload_closure ' 'load_genexpr %s ' 'expr GET_ITER CALL_FUNCTION_1' % ('pos_arg ' * token.attr, opname), opname, token.attr, customize) if self.version >= 3.3: self.add_unique_rule('listcomp ::= %sload_closure ' 'LOAD_LISTCOMP LOAD_CONST %s expr ' 'GET_ITER CALL_FUNCTION_1' % ('expr ' * token.attr, opname), opname, token.attr, customize) else: self.add_unique_rule('listcomp ::= %sload_closure ' 'LOAD_LISTCOMP %s expr ' 'GET_ITER CALL_FUNCTION_1' % ('expr ' * token.attr, opname), opname, token.attr, customize) self.add_unique_rule('setcomp ::= %sload_closure LOAD_SETCOMP %s expr ' 'GET_ITER CALL_FUNCTION_1' % ('expr ' * token.attr, opname), opname, token.attr, customize) self.add_unique_rule('dictcomp ::= %sload_closure LOAD_DICTCOMP %s ' 'expr GET_ITER CALL_FUNCTION_1' % ('pos_arg '* token.attr, opname), opname, token.attr, customize) rule = ('mkfunc ::= %s load_closure LOAD_CONST %s' % ('expr ' * token.attr, opname)) # Python 3.5+ instead of above? rule = ('mkfunc ::= %s load_closure LOAD_CONST LOAD_CONST %s' % ('expr ' * token.attr, opname)) self.add_unique_rule(rule, opname, token.attr, customize) rule = ('mkfunc ::= %s load_closure load_genexpr %s' % ('pos_arg ' * token.attr, opname)) self.add_unique_rule(rule, opname, token.attr, customize) rule = ('mkfunc ::= %s load_closure LOAD_CONST %s' % ('expr ' * token.attr, opname)) self.add_unique_rule(rule, opname, token.attr, customize) return class Python32Parser(Python3Parser): def p_32(self, args): """ # Store locals is only in Python 3.2 and 3.3 designator ::= STORE_LOCALS """ class Python33Parser(Python3Parser): def p_33(self, args): """ # Store locals is only in Python 3.2 and 3.3 designator ::= STORE_LOCALS """ class Python34Parser(Python3Parser): def p_34(self, args): """ _ifstmts_jump ::= c_stmts_opt JUMP_FORWARD _come_from """ class Python35onParser(Python3Parser): def p_35on(self, args): """ # Python 3.5+ has WITH_CLEANUP_START/FINISH withstmt ::= expr SETUP_WITH with_setup suite_stmts_opt POP_BLOCK LOAD_CONST COME_FROM WITH_CLEANUP_START WITH_CLEANUP_FINISH END_FINALLY withasstmt ::= expr SETUP_WITH designator suite_stmts_opt POP_BLOCK LOAD_CONST COME_FROM WITH_CLEANUP_START WITH_CLEANUP_FINISH END_FINALLY # Python 3.5 has more loop optimization that removes # JUMP_FORWARD in some cases, and hence we also don't # see COME_FROM _ifstmts_jump ::= c_stmts_opt """ class Python3ParserSingle(Python3Parser, PythonParserSingle): pass class Python32ParserSingle(Python32Parser, PythonParserSingle): pass class Python33ParserSingle(Python33Parser, PythonParserSingle): pass class Python34ParserSingle(Python34Parser, PythonParserSingle): pass class Python35onParserSingle(Python35onParser, PythonParserSingle): pass if __name__ == '__main__': # Check grammar p = Python3Parser() p.checkGrammar()