Python Language Tutorial => Manage Resources

Example

class File():
    def __init__(self, filename, mode):
        self.filename = filename
        self.mode = mode

    def __enter__(self):
        self.open_file = open(self.filename, self.mode)
        return self.open_file

    def __exit__(self, *args):
        self.open_file.close()

__init__() method sets up the object, in this case setting up the file name and mode to open file. __enter__() opens and returns the file and __exit__() just closes it.

Using these magic methods (__enter__, __exit__) allows you to implement objects which can be used easily with the with statement.

Use File class:

for _ in range(10000):
    with File('foo.txt', 'w') as f:
        f.write('foo')

PDF - Download Python Language for free

Previous Next

Python Language

Fastest Entity Framework Extensions

Example

Got any Python Language Question?

Python Language

Python Language Context Managers (“with” Statement) Manage Resources

Fastest Entity Framework Extensions

Example

Got any Python Language Question?