file.flush() Flush buffer
Last updated: 2026-09-22
file.flush() Flush buffer
file.flush() forces the internal buffer to be written to disk without closing.
| Category | File Methods |
|---|---|
| Kind | Built-in Type Method |
| Python Version | all |
📝 Syntax
file.flush()Returns：None. Forces buffered data to disk without closing the file.
Mutates the original：No (returns a new object)
💥 Raises
OSError— Raised when writing to disk fails.
▶ Example
Edit the code, press Run, and see the result in the output panel:
Output：
3💡 Related Cases
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❓ FAQ
QWhat does flush() do?
AIt forces buffered data to be written to disk, without closing the file.
QIs data lost if I do not flush?
ANormal program exit, close(), and the end of a with block all flush automatically; however, on a process crash buffered data can be lost. For scenarios needing immediate disk write, such as logs, call flush() manually.
QWhat is the difference between flush() and close()?
Aflush() only flushes the buffer and the file can still be written; close() closes the file (internally flushing once first).
