我如何检查给定的部分或不完整的 python 程序在语法上是否正确

Question

我如何编写一个程序来解析不完整的 return 如果到目前为止的标记字符串可能生成句法正确的 python 程序则为真 python 如果句法不正确则为假 python程序可以永远生成。

这是一个例子。

programs = ["def foo():", "def ():", "def foo(): return ", "def foo(x):\n  else"]

def check(program):
  '''
  returns True if program can be possibly completed as a valid python 
  program else False if there doesn't exist any string which can 
  be appended after the 'program' to make it valid python program.
  '''
  pass

print([check(program) for program in programs])
>> [True, False, True, False]

我知道我可以使用 antlr-python 运行time 来检查运行解析器以适当的顺序检查语法扩展规则，但我需要纯 python 解决方案。我可以仅使用 python ast 模块来执行此操作吗？如果不能，我如何使用 python-antlr-运行time.

来执行此操作？

Answer 1

我被管理到这个antlr，这是我的解决方案

from antlr4 import *
from antlr4.error import ErrorListener
from Python3Lexer import Python3Lexer
from Python3Parser import Python3Parser


class MyErrorListener(ErrorListener.ErrorListener):

  def syntaxError(self, recognizer, offendingSymbol, line, column, msg, e):
    if offendingSymbol.type == -1:
      pass
    else:
      raise Exception("syntaxError")

  def reportAmbiguity(self, recognizer, dfa, startIndex, stopIndex, exact, ambigAlts, configs):
    raise Exception("reportAmbiguity")

  def reportAttemptingFullContext(self, recognizer, dfa, startIndex, stopIndex, conflictingAlts, configs):
    raise Exception("reportAttemptingFullContext")

  def reportContextSensitivity(self, recognizer, dfa, startIndex, stopIndex, prediction, configs):
    raise Exception("reportContextSensitivity")


def check(program):

  try:
    input_stream = InputStream(program)
    lexer = Python3Lexer(input_stream)
    stream = CommonTokenStream(lexer)
    parser = Python3Parser(stream)
    parser.addErrorListener(MyErrorListener())

    parser.file_input()
    return True
  except Exception:
    return False


if __name__ == '__main__':
  programs = ["def foo():", "def ():", "def foo(): return ", "def foo(x):\n  else"]
  print([check(program) for program in programs])

我如何检查给定的部分或不完整的 python 程序在语法上是否正确

How can I check given partial or incomplete python program is syntacticly correct or not

python

parsing

abstract-syntax-tree

antlr4