How to Write to a Text File in Python: Absolute Beginners Tutorial

Writing to a text file is one of the first practical things you will do in Python. Once you know how, you can save program output, log data, store user input, and build tools that remember information between runs.

Python gives you a built-in function called open() for working with files. You do not need to install anything extra. Understanding two things — which mode to use and how to close the file properly — gets you most of the way there.

The open() Function and Write Modes

The open() function takes a filename (and optionally a path) as its first argument, and a mode string as its second. For writing, the two modes you need to know are 'w' and 'a'.

The safest way to open a file in Python is with a context manager — a with statement. It closes the file automatically when the indented block finishes, even if something goes wrong inside the block.

# Open a file for writing using a context manager
with open("notes.txt", "w", encoding="utf-8") as f:
    f.write("Hello from Python!")

# The file is closed automatically when the with block ends

The variable f is the file object. You call methods on it — like .write() — to interact with the file. The name f is a convention; you can use any valid variable name.

The comparison table below shows the four most common file modes and what each one does.

Writing Text and Handling Newlines

The .write() method accepts a single string and writes it to the file. It returns the number of characters written, though you typically do not need to use that return value.

# Writing multiple lines — \n creates the line break
with open("shopping.txt", "w", encoding="utf-8") as f:
    f.write("Apples\n")
    f.write("Bread\n")
    f.write("Coffee\n")

# Result in shopping.txt:
# Apples
# Bread
# Coffee

Writing a list of items with a loop is a cleaner approach when you have several lines to write.

items = ["Apples", "Bread", "Coffee", "Eggs"]

with open("shopping.txt", "w", encoding="utf-8") as f:
    for item in items:
        f.write(item + "\n")

Python also provides a .writelines() method that accepts an iterable of strings and writes each one in sequence. Like .write(), it does not add newlines automatically — you must include them in each string.

lines = ["Line one\n", "Line two\n", "Line three\n"]

with open("output.txt", "w", encoding="utf-8") as f:
    f.writelines(lines)

Appending vs. Overwriting

Every time you open a file with 'w' mode, Python erases everything in it before writing. This is the right choice when you want a clean slate, but it causes data loss if you wanted to keep previous content.

Use 'a' mode whenever you want to preserve what is already in the file.

# First run — creates the file and writes the first entry
with open("events.txt", "a", encoding="utf-8") as f:
    f.write("2026-04-05 09:00 — Server started\n")

# Second run — adds a new entry without erasing the first
with open("events.txt", "a", encoding="utf-8") as f:
    f.write("2026-04-05 09:15 — User logged in\n")

After both runs, events.txt contains two lines. If you had used 'w' on the second run, only the second line would remain.

According to the official Python documentation, when no mode is specified, open() defaults to 'r' — reading text. This is also written as 'rt', confirming that text mode is the implicit baseline. — Python Software Foundation, docs.python.org/3/library/functions.html

# Complete example — write a list of scores to a file
scores = [95, 87, 72, 100, 66]

with open("scores.txt", "w", encoding="utf-8") as f:
    f.write("Score Report\n")
    f.write("============\n")
    for i, score in enumerate(scores, start=1):
        f.write(f"Student {i}: {score}\n")

# Append a summary line later
with open("scores.txt", "a", encoding="utf-8") as f:
    average = sum(scores) / len(scores)
    f.write(f"\nAverage: {average:.1f}\n")

Key Takeaways

1. Use open(filename, "w", encoding="utf-8") to create or overwrite a file, and open(filename, "a", encoding="utf-8") to add to an existing one without erasing it.
2. Always prefer a with statement — it closes the file automatically and prevents data from being lost if an error occurs.
3. The .write() method only accepts strings. Convert integers and floats with str() or use f-strings before passing them to .write().
4. Newlines are your responsibility. Add \n to the end of each string if you want each piece of text to appear on its own line in the file.
5. Always pass encoding="utf-8" to open(). Without it Python uses the OS default, which is cp1252 on Windows — a silent cross-platform bug that only surfaces when someone outside Mac/Linux runs your script.

File I/O is one of those skills that shows up constantly once you start writing real programs. With open(), .write(), and a solid understanding of modes, you have everything you need to save data from any Python script.