How Can I Efficiently Process Large Text Files Line by Line to Avoid Memory Issues?

Reading Large Text Files Line by Line, Memory-Efficiently

To process large text files without overwhelming your memory, we explore an approach that reads them a line at a time, without loading their entire contents.

Solution:

The key is to iterate over the file object itself, using a for loop:

with open("log.txt") as infile:
    for line in infile:
        print(line)

By using a context manager (with open(...)), we ensure the file is properly closed after processing.

How it Works:

The open() function returns a file object that supports iteration. Each line in the file is represented as a string, and the loop iterates over these lines. This allows you to process each line individually without having to load the entire file into memory.

Example Usage:

Assuming log.txt is a large text file, the code would read it line by line as follows:

with open("log.txt") as infile:
    for line in infile:
        # Perform operations on each line here (e.g., print, write to another file)

Advantages:

• Memory-efficient: Only a single line is loaded into memory at a time.
• Scalable: Can be used for processing large files, even those with billions of lines.
• Simple and portable: Works across various platforms and programming environments.

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