CODEWITHSUNDEEP
pythonpython-3.xwith-statement
Henry Kim
Henry Kim

Reputation: 585

Is there any potential vuln when use as object after with statement?

I'm using python3.6 in virtualenv. And I wonder if I use with object from outside with statement.

This is example code for the question.

with tempfile.NamedTemporaryFile(delete=False) as tf:
    tf.write(audio_stream)

# outside of with
print(tf.name)  # is it dangerous?

I want to do only write in with statement, and do other stuff outside of with. (Such as tf.name). Is there a potential threat to access the tf object from outside with? (Unintentional garbage collection, etc.)

If that's not recommended, I wonder the exact reason as well. thanks

Upvotes: 1

Views: 41

Answers (1)

tdelaney
tdelaney

Reputation: 77337

There is no unintentional garbage collection. Each class of object decides what exiting the with means to it, so there is no hard rule. Typically held-resources like an underlying file handle are closed but other attributes that don't normally change during a close are unchanged.

In your case, the temp file is closed so read/write/seek etc... don't work but the name attribute is safe to read.

If you really need to know for a given object, open its source and look at its __exit__ method.

Upvotes: 1

Related Questions