Context Management

Describing Context Management

• A context manager refers to any object that can be executed using the with statement
• The general syntax is as follows:

with context [as var]:
    statements

• __enter__() is invoked when the with statement executes
• The value returned by this method is placed into the variable specified as [as var]
• It is then passed through to the remainder of the with block
• __exit__() is invoked at the end of a with statement
• Primarily, the context management interface allows for simplified field resource control on objects involving system state
• By implementing this interface, objects can safely clean up resources when execution leaves a context

• Examples of objects involving system state are:

  • Open files
  • Network connections
  • Locks

Summarizing Special Methods

References

• Python Essential Reference