The code below creates a "tee" object that tees stdout to a file as well as the terminal.

If do del t as below when I'm done tee-ing, the object doesn't get deleted and the __del__()<,python"/>

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The code below creates a "tee" object that tees stdout to a file as well as the terminal.

If do del t as below when I'm done tee-ing, the object doesn't get deleted and the __del__()<

python - 为什么不del delete it?

The code below creates a "tee" object that tees stdout to a file as well as the terminal.

If do del t as below when I'm done tee-ing, the object doesn't get deleted and the __del__()<

问题描述

The code below creates a "tee" object that tees stdout to a file as well as the terminal.

If do del t as below when I'm done tee-ing, the object doesn't get deleted and the __del__() member doesn't get called (so the tee-ing continues):

t = tee("foo.txt")
print("bar")
del t

But if I call __del__() directly, things work fine:

t = tee("foo.txt")
print("bar")
t.__del__()

Why doesn't the del work? What's the right way to do this?

class tee():
    def __init__(self, filepath):
        self.old_stdout = sys.stdout
        self.old_stderr = sys.stderr
        self.name = filepath

        sys.stdout = self
        sys.stderr = self

    def write(self, text):
        self.old_stdout.write(text)
        with open(self.name, 'a',  encoding="utf-8") as f:
           f.write(text)

    def flush(self):
        pass

    def __del__(self):
        sys.stdout = self.old_stdout
        sys.stdout = self.old_stderr

It's unclear exactly what it is you're trying to do, but your start_timer function is an infinite busy loop that will hang your GUI, so I assume that's not it! Maybe you meant to call Tk.after?

def start_timer(x=0):
    x+=1
    Screen.after(1000, lambda x=x: start_timer(x))
    # 1000 is the time (in milliseconds) before the callback should be invoked again
    # lambda x=x... is the callback itself. It binds start_timer's x to the scope of
    # the lambda, then calls start_timer with that x.
    itemconfigure(aText,text=x)

I'm going out on a limb and say that you expect itemconfigure(aText, text=x) to change the text on the label? You should instead be using:

    ...
    aText.config(text=x)

标签： python

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