Python seek() Method

The seek() method in Python is used to change the file pointer’s position within a file. It is a method of the file object, allowing you to move the pointer to a specific location, which is useful for reading or writing data at different parts of a file.

1. Syntax

file.seek(offset, whence)
    

• offset: The number of bytes to move the file pointer. It can be positive or negative.
• whence: Optional. The reference point for the offset. It can be:
  • 0: Start of the file (default).
  • 1: Current file position.
  • 2: End of the file.

2. Example Usage

Here’s a simple example demonstrating how to use the seek() method:

# Open a file in read mode
with open('example.txt', 'r') as file:
    # Read the first 5 bytes
    content = file.read(5)
    print('Content read:', content)
    
    # Move the file pointer to the beginning of the file
    file.seek(0)
    
    # Read the entire file again
    full_content = file.read()
    print('Full content:', full_content)
    
    # Move the file pointer to a specific position
    file.seek(10)
    # Read from position 10 to the end
    remaining_content = file.read()
    print('Content from position 10:', remaining_content)
    

3. Explanation

• Opening the File: The file is opened in read mode using the with statement to ensure it is properly closed after use.
• Reading Data: The first 5 bytes are read from the file.
• Using seek(): The seek(0) method moves the file pointer to the beginning of the file, allowing the file to be read again from the start. The seek(10) method moves the pointer to the 10th byte of the file.

4. Use Cases

The seek() method is particularly useful for:

• Re-reading or skipping parts of a file.
• Implementing custom file operations, such as reading from specific offsets or writing data to specific locations.
• Handling binary files where exact positioning is required.

5. Conclusion

The seek() method is an essential tool for file manipulation in Python, allowing you to control the file pointer’s position. Understanding how to use seek() can enhance your ability to perform efficient file operations and manage file data effectively.