Mode

Definition

Mode specifies how a file should be opened when performing read or write operations in Python. Common modes include 'r' for reading, 'w' for writing, and 'a' for appending.

5 Must Know Facts For Your Next Test

1. The mode 'w' will truncate the file to zero length if it already exists, otherwise, it creates a new file.
2. Using mode 'a' will append data to the end of the file without truncating it.
3. 'r+' allows both reading and writing but requires that the file already exists.
4. 'b' can be added to any mode (e.g., 'wb', 'rb') to indicate binary mode, which is necessary for non-text files.
5. Using context managers with the 'with' statement ensures proper handling of files and automatic closing.

Review Questions

• What happens when you open a file in 'w' mode that already exists?
• How do you open a file for both reading and writing?
• Why would you use the binary mode (e.g., 'wb') instead of text mode?

Related terms

Context Manager: A feature in Python that provides a way to allocate and release resources precisely when you want to using the 'with' statement.

'r+' Mode: 'r+' opens an existing file for both reading and writing. The file pointer is placed at the beginning of the file.

'a' Mode: 'a' opens a file for appending data at the end of the file without truncating it. Creates a new file if it does not exist.