سلام دوستان روزتون به خیر.
خیلی دقیق نتونستم کلمه کلیدی with رو درک کنم اکر امکانش هست توضیح بدید ممنون میشم.
این یک نمونه مثال
>>> with open(’/tmp/workfile’, ‘r’) as f:
… read_data = f.read()
یک توضیحات انگلیسی هم داخلش پیدا کردم. که اینو نوشته بود . راجب enter و exit توضیح داده . ولی من متوجه نمیشم
with
with
statement is used to wrap the execution of a block of code within methods defined by the context manager.
Context manager is a class that implements __enter__
and __exit__
methods. Use of with
statement ensures that the __exit__
method is called at the end of the nested block. This concept is similar to the use of try…finally
block. Here, is an example.
with open('example.txt', 'w') as my_file:
my_file.write('Hello world!')
This example writes the text Hello world!
to the file example.txt
. File objects have __enter__
and __exit__
method defined within them, so they act as their own context manager.
First the __enter__
method is called, then the code within with
statement is executed and finally the __exit__
method is called. __exit__
method is called even if there is an error. It basically closes the file stream.