How Can I Read a File Line by Line into a Python List?

Line-by-Line File Reading with Python Lists

To read a file line by line and store each line as an element in a Python list, follow these steps:

1. Open the File:

Start by opening the file in read-only mode:

with open(filename, 'r') as file:
    # ...

2. Read and Process the File:

To read the entire file into memory and remove whitespace characters from the ends of each line, use a list comprehension:

with open(filename, 'r') as file:
    lines = [line.rstrip() for line in file]

For large files, consider reading and processing the file line-by-line to avoid memory issues:

with open(filename, 'r') as file:
    for line in file:
        print(line.rstrip())

3. Use the Walrus Operator for Python 3.8 and Above:

In Python 3.8 and later, you can use a while loop with the walrus operator:

with open(filename, 'r') as file:
    while line := file.readline():
        print(line.rstrip())

4. Set Access Mode and Character Encoding:

For specific file handling requirements, you can manually set the access mode and character encoding:

with open(filename, 'r', encoding='UTF-8') as file:
    # ...

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