Close
Close is an operation that terminates access to an associated resource or interface and releases or finalizes related resources or pending work.
A Pythonic Adventure: From Python basics to a working web app
A file close method terminates an open file connection and releases its associated resources.
- How it is used
- Closes files after each order read or write in a Flask web application.
- How deep it goes
- Demonstrates placement after JSON operations and notes the performance tradeoff, without exploring alternative file-management techniques.
- Examples
- Uses save_orders() and load_orders() with orders.json to demonstrate closing after writing and reading.
- What you can do after
- Apply Python's f.close() method after reading or writing an order file.
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100 Go Mistakes and How to Avoid Them
A Close method terminates or releases an associated resource and reports whether that operation produced an error.
- How it is used
- Releases database rows and file descriptors while making cleanup failures visible when they affect correctness or operations.
- How deep it goes
- Traces deferred execution, error propagation, buffered writes, and synchronization, but defers broader database and package details.
- Examples
- Uses sql.Rows cleanup, writable os.File output, logging, named results, and deferred closures.
- What you can do after
- Diagnose deferred cleanup failures and choose whether to ignore, log, propagate, or precede Close with Sync.
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Learn AI-Assisted Python Programming, Second Edition
The close method releases a file object's resources and ends access to the associated file.
- How it is used
- Closes a file after reading or processing it, ending access to the associated resource.
- How deep it goes
- Defines the operation and its access restriction, but does not explore lower-level resource-management internals.
- Examples
- Demonstrates closing an NFL statistics file after looping through its lines.
- What you can do after
- Operate/configure it by explicitly closing a file after completing its processing.
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Learn SQL in a Month of Lunches
CLOSE is a cursor operation that terminates cursor use and releases its associated resources.
- How it is used
- Releases cursor contents after row processing finishes.
- How deep it goes
- Defines CLOSE within the required DECLARE, OPEN, FETCH, and CLOSE order, but defers deallocation differences among database systems.
- Examples
- Demonstrates CLOSE AllOrders after a loop that totals qualifying book quantities by order.
- What you can do after
- Operate/configure a cursor lifecycle by closing it after fetching and processing its result set.
Related concepts
- cursorpart of · A database cursor is an object or interface that executes database operations and incrementally retrieves or traverses their result rows.
- file objectused by · A file object is a program-accessible representation of an open file or stream, including its access state and input/output operations.
- deferused by · Defer is a language feature that schedules an operation to execute when the surrounding function or scope exits, including during exceptional unwinding.
- booleanuses · A Boolean is a logical type or value representing truth or falsity, conventionally with two states: true and false.
- errnouses · errno is a C library macro identifying a modifiable integer error indicator associated with the current thread or execution context.
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