What are the Differences Between Python's `open()` Function Modes: 'r', 'w', 'a', 'r ', 'w ', and 'a '?

Understanding Modes in the Python Open Function

The open function in Python offers various modes to manipulate files. Besides the well-known read-only mode 'r', there are additional options for writing and updating. The following modes share the ability to write to files but differ in their exact functionality:

• 'w': Opens a file for writing. If the file exists, it truncates (empties) its contents. The cursor starts at the beginning.
• 'a': Opens a file for writing and appends to the end. If the file doesn't exist, it's created.
• 'w ': Same as 'w', but allows for reading and writing. The cursor is initially at the beginning.
• 'a ': Similar to 'a', but also allows for reading. The cursor is placed at the end initially.
• 'r ': Opens a file for both reading and writing. The file must already exist, and the cursor is positioned at the start.

It's important to note that the behaviors of these modes are based on the C standard library function fopen(). The BSD fopen manpage provides detailed explanations of each mode, emphasizing their functions in both text and binary operations.

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