Why is it advised to close a file after we are done with the read and write operations? What will happen if we do not close it? Will some error message be flashed?
It is advised to close a file after read/write operations because when we close a file, the system frees the memory allocated to it. Also, Python ensures that any unwritten or unsaved data is flushed (written) to the file before it is closed.
If we do not close the file, the memory allocated to the file remains occupied and is not freed. The unwritten or unsaved data may not be written to the file, leading to potential data loss.
The provided context does not explicitly mention whether an error message will be flashed. However, it states that if the file object is re-assigned to some other file, the previous file is automatically closed.
Explanation
The textbook in section 2.3.2 clearly explains the importance of closing files. The close() method frees memory and ensures unwritten data is flushed to the file. The context does not provide explicit information about error messages being displayed when files are not closed - it only mentions automatic closure upon reassignment of the file object.