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我正在尝试编写一个小脚本来检查作为命令行参数传递的文件是否正确或错误地括号括起来。

我创建了一个异常来处理函数停止点，但似乎无法正确提升它。

当我在 Python 解释器中测试代码时，它似乎可以工作（即它识别它应该引发异常，但是当我用我拥有的示例文件（括号严重）测试我的文件时，它仍然打印出它已成功检查

你有什么想法 ？

最好的，

代码 ：

import sys
from stack import *


class BracketException(Exception) :
    """
    Exception qui gère les problèmes de parenthesage : mauvaise parenthèse,
    mauvais placement etc...
    """

    def __init__(self, char, lineNumber, charNumber) :
        self.char = char
        self.lineNumber = lineNumber
        self.charNumber = charNumber

    def __str__(self) :
        return(self.char + " at line " + str(self.lineNumber) + " char " + str(self.charNumber))


def checker(file) :
    lineNumber = 1
    charNumber = 1

    stacked = Stack()
    openers = ["(", "[", "{"]
    closers = [")", "]", "}"]

    inChannel = open(file, "r")

    for line in file :
        for char in line :
            if char in openers :
                stacked.push([char, lineNumber, charNumber])
                print(stacked.top())
            elif char in closers :
                try :
                    if openers[closers.index(char)] == stacked.top()[0] :
                        stacked.pop()
                    else :
                        raise BracketException(char, lineNumber, charNumber)
                except StackEmptyError :
                    raise BracketException(char, lineNumber, charNumber)

            charNumber += 1
        charNumber = 1
        lineNumber += 1

    inChannel.close()

    if not stacked.is_empty() :
        raise BracketException(stacked.top()[i] for i in range(3))

def __main__() :

    try :
        fichier = sys.argv[1]
        checker(fichier)
        print("it's checked !")
    except BracketException as ex :
        print(ex)
    except IndexError :
        print("Wrong number of parameters")
    except Exception as e :
        print(e)

if __name__ == "__main__" :
    __main__()
4

1 回答 1

3

您正在迭代给定的文件名，而不是创建的文件句柄。文件名中可能没有不平衡的括号，因此也不例外。

def checker(file) :
    lineNumber = 1
    charNumber = 1

    stacked = Stack()
    openers = ["(", "[", "{"]
    closers = [")", "]", "}"]

    inChannel = open(file, "r")  # file handle is inChannel

    for line in file :  #  iterating over file name, not file handle

你应该切换到

with open(file, "r") as inChannel:
    for line in inChannel :

即使抛出异常也要确保关闭文件 - 这是文件处理的首选方式，请参阅docs.python.org - 读取和写入文件

我无法对此进行测试（没有堆栈模块 - 如果需要，我使用列表），但这应该更快：

def checker(filename) :
    lineNumber = 1
    charNumber = 1

    stacked = Stack()

    openers = set( "{[(")  # sets are better suited for test of "in"
    closers = set( "}])")  # same

    # mapping between closing bracket at hand and what should be on the stack
    # also faster then .index()ing into a list
    open_for_close = { ")":"(","}":"{","]":"[" }

    with open(filename, "r") as f:
        for line in f:            # iterate over the filehandle 
            for char in line:
                if char in openers:
                    stacked.push([char, lineNumber, charNumber])
                    print(stacked.top())
                elif char in closers:
                    try :
                        if open_for_close[char] == stacked.top()[0] :
                            stacked.pop()
                        else :
                            raise BracketException(char, lineNumber, charNumber)
                    except StackEmptyError :
                        raise BracketException(char, lineNumber, charNumber)
                charNumber += 1
            charNumber = 1
            lineNumber += 1

    if not stacked.is_empty() :
        raise BracketException(stacked.top()[i] for i in range(3))
于 2018-10-29T21:36:43.157 回答