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Python等价于C#的using语句[重复]

using ironpython python

5

Mark Heath · 技术社区 · 14 年前

可能重复:
What is the equivalent of the C# “using” block in IronPython?

我正在使用一些一次性的.NET对象编写一些IronPython,并想知道是否有一种很好的“pythonic”方法来实现这一点。目前我有一堆finally语句(我想每个语句中也应该有一个都不存在的检查——或者如果构造函数失败了变量就不存在了?)

def Save(self):
    filename = "record.txt"
    data = "{0}:{1}".format(self.Level,self.Name)
    isf = IsolatedStorageFile.GetUserStoreForApplication()
    try:                
        isfs = IsolatedStorageFileStream(filename, FileMode.Create, isf)
        try:
            sw = StreamWriter(isfs)
            try:
                sw.Write(data)
            finally:
                sw.Dispose()
        finally:
            isfs.Dispose()
    finally:
        isf.Dispose()

4 回复 | 直到 7 年前

1

6

Community CDub 7 年前

Python2.6引入了 with 具有 陈述。我不知道IronPython库是否支持它,但这是自然的。

What is the equivalent of the C# "using" block in IronPython?

2

1

Damian Schenkelman 14 年前

我想你在找 with statement . 更多信息 here

3

0

Daniel Roseman 14 年前

如果我理解正确的话,它看起来相当于 with 陈述。如果类定义了上下文管理器,则它们将在with块之后自动调用。

4

0

kriss 14 年前

您的代码带有一些注释:

def Save(self):
    filename = "record.txt"
    data = "{0}:{1}".format(self.Level,self.Name)
    isf = IsolatedStorageFile.GetUserStoreForApplication()
    try:                
        isfs = IsolatedStorageFileStream(filename, FileMode.Create, isf)

        try: # These try is useless....
            sw = StreamWriter(isfs)
            try:
                sw.Write(data)
            finally:
                sw.Dispose()
        finally: # Because next finally statement (isfs.Dispose) will be always executed
            isfs.Dispose()
    finally:
        isf.Dispose()

对于StreamWrite,可以使用with statent(如果对象为 __ 进入 __ 和 出口 __

def Save(self):
    filename = "record.txt"
    data = "{0}:{1}".format(self.Level,self.Name)
    isf = IsolatedStorageFile.GetUserStoreForApplication()
    try:                
        isfs = IsolatedStorageFileStream(filename, FileMode.Create, isf)
        with StreamWriter(isfs) as sw:
            sw.Write(data)
    finally:
        isf.Dispose()

和他的流线型作家 __ __ 方法有

sw.Dispose()