Write File

Zero-dependency Python snippets for writing files using the standard library.

4 snippets available in this sub-category.

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Simple

Write string to file

file write string open

Write a string to a file, overwriting existing content

with open("file.txt", "w") as f:
    f.write("Hello, World!")

Notes

• Use 'w' mode to overwrite existing file
• Creates new file if it doesn't exist
• File is automatically closed after writing

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Write with encoding

file write encoding utf-8

Write file with specific encoding

with open("file.txt", "w", encoding="utf-8") as f:
    f.write("Hello, 世界!")

Notes

• Always specify encoding for international text
• UTF-8 handles most characters properly
• Prevents encoding issues

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Complex

Write file with error handling

file write error-handling function encoding

Write file with comprehensive error handling

def write_file_safe(filename, content, encoding="utf-8"):
    """Write content to file with comprehensive error handling."""
    try:
        with open(filename, "w", encoding=encoding) as f:
            f.write(content)
        return True
    except PermissionError:
        print(f"Error: No permission to write to '{filename}'")
        return False
    except OSError as e:
        print(f"Error writing to '{filename}': {e}")
        return False


success = write_file_safe("file.txt", "Hello, World!")
if success:
    print("File written successfully")

Notes

• Handles common file writing errors
• Returns boolean for success/failure
• Supports custom encoding
• Provides helpful error messages

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Write file atomically

file write atomic tempfile os

Write file atomically to prevent corruption during writing

import os
import tempfile


def write_file_atomic(filename, content, encoding="utf-8"):
    """Write file atomically to prevent corruption."""
    temp_file = tempfile.NamedTemporaryFile(
        mode="w", encoding=encoding, delete=False, dir=os.path.dirname(filename)
    )

    try:
        temp_file.write(content)
        temp_file.close()
        os.replace(temp_file.name, filename)
        return True
    except Exception as e:
        print(f"Error writing file: {e}")
        try:
            os.unlink(temp_file.name)
        except Exception:
            pass
        return False


write_file_atomic("important.txt", "Critical data")

Notes

• Uses temporary file to prevent corruption
• Atomic operation ensures file integrity
• Cleans up temporary file on error
• Useful for critical data files

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🔗 Cross-References

• Reference: See 📂 Append File
• Reference: See 📂 Read File

🏷️ Tags

file, write, text, overwrite, io

📝 Notes

• Use open() with mode 'w' to write (overwrite) files
• Overwrites existing content by default
• Useful for saving data and reports