Python Rename File - Complete Guide with Examples

What You'll Learn Here

os.rename() — the primary way to rename files
Pattern renaming — adding prefixes and suffixes
Batch renaming — renaming multiple files at once
Changing extensions — updating file types
Error handling — handling common rename errors
Best practices — safe file renaming

Renaming Files in Python

Renaming files is a common task when organizing data, updating file names, or standardizing naming conventions. Python makes it easy to rename files using the os.rename() function from the os module.

Think of renaming a file like updating the label on a folder. The contents stay the same, but the name changes. Python lets you do this programmatically, which is especially useful when you need to rename hundreds of files at once.

💡 Key concept: When you rename a file, you're changing its name while keeping the content intact. This is useful for organizing files, fixing naming errors, or standardizing file names across a project.

Using os.rename()

The Primary Way to Rename Files

# First, let's create a file to work with
with open("old_name.txt", "w") as f:
    f.write("This is a sample file\n")
    f.write("We'll rename this file.")
print(" Created: old_name.txt")

# The os.rename() function takes two arguments:
# 1. The current file name (old name)
# 2. The new file name (new name)

import os

# 1. Basic rename
os.rename("old_name.txt", "new_name.txt")
print(" Renamed: old_name.txt → new_name.txt")

# 2. Verifying the rename
print("\n📁 Files in current directory:")
for file in os.listdir("."):
    if file.endswith(".txt"):
        print(f"   {file}")

# 3. Renaming with full paths
# os.rename("data/old_file.txt", "data/new_file.txt")

# 4. Renaming to a different directory
# os.rename("file.txt", "archive/file.txt")

# 5. Renaming a file with spaces
# os.rename("old file.txt", "old_file.txt")

# 6. Using os.path for safer operations
def safe_rename(old_name, new_name):
    """Safely rename a file with path handling"""
    import os
    try:
        os.rename(old_name, new_name)
        print(f" Renamed: {old_name} → {new_name}")
        return True
    except Exception as e:
        print(f" Error: {e}")
        return False

# Test the function
safe_rename("new_name.txt", "final_name.txt")

os.rename() key points:

Two arguments — old name and new name
Full paths — can include directory paths
Overwrites — if new name exists, it will be replaced
Cross-platform — works on Windows, Linux, macOS
OS module — must import os first

Quick Check: What function is used to rename files in Python? (Answer: os.rename())

Renaming with Patterns

Adding Prefixes, Suffixes, and More

# Create sample files first
for i in range(3):
    with open(f"sample_{i}.txt", "w") as f:
        f.write(f"Sample file {i}")

import os

# 1. Adding a prefix to a file name
def add_prefix(filename, prefix):
    """Add a prefix to a filename"""
    new_name = f"{prefix}{filename}"
    os.rename(filename, new_name)
    print(f"Renamed: {filename} → {new_name}")

# 2. Adding a suffix
def add_suffix(filename, suffix):
    """Add a suffix to a filename (before extension)"""
    name, ext = os.path.splitext(filename)
    new_name = f"{name}{suffix}{ext}"
    os.rename(filename, new_name)
    print(f" Renamed: {filename} → {new_name}")

# 3. Replacing text in filenames
def replace_in_name(filename, old_text, new_text):
    """Replace text in a filename"""
    new_name = filename.replace(old_text, new_text)
    os.rename(filename, new_name)
    print(f" Renamed: {filename} → {new_name}")

# 4. Adding a date stamp
import datetime

def add_timestamp(filename):
    """Add a timestamp to a filename"""
    name, ext = os.path.splitext(filename)
    timestamp = datetime.datetime.now().strftime("%Y%m%d")
    new_name = f"{name}_{timestamp}{ext}"
    os.rename(filename, new_name)
    print(f" Renamed: {filename} → {new_name}")

# 5. Converting to lowercase
def lowercase_filename(filename):
    """Convert filename to lowercase"""
    new_name = filename.lower()
    os.rename(filename, new_name)
    print(f" Renamed: {filename} → {new_name}")

# Test the functions with sample files
add_prefix("sample_0.txt", "project_")
add_suffix("sample_1.txt", "_v2")
replace_in_name("sample_2.txt", "sample", "data")
add_timestamp("project_sample_0.txt")
lowercase_filename("project_sample_0_20260808.txt")

Pattern renaming techniques:

Prefix — add text at the beginning
Suffix — add text before the extension
Replace — change specific text in the name
Timestamp — add current date/time
Case changes — convert to lowercase or uppercase

Quick Check: How would you add a prefix to a filename? (Answer: new_name = prefix + filename)

Batch Renaming Files

Renaming Multiple Files at Once

import os

# Create sample files first
for i in range(5):
    with open(f"file_{i}.txt", "w") as f:
        f.write(f"This is file {i}")

# 1. Rename all files in a directory
def rename_all_files(directory, prefix=""):
    """Rename all files in a directory with a prefix"""
    for filename in os.listdir(directory):
        if os.path.isfile(os.path.join(directory, filename)):
            new_name = f"{prefix}{filename}"
            os.rename(
                os.path.join(directory, filename),
                os.path.join(directory, new_name)
            )
            print(f" Renamed: {filename} → {new_name}")

rename_all_files(".", "data_")

# 2. Rename files matching a pattern
def rename_matching_files(directory, pattern, new_pattern):
    """Rename files matching a pattern"""
    for filename in os.listdir(directory):
        if pattern in filename:
            new_name = filename.replace(pattern, new_pattern)
            os.rename(
                os.path.join(directory, filename),
                os.path.join(directory, new_name)
            )
            print(f" Renamed: {filename} → {new_name}")

rename_matching_files(".", "file", "document")

# 3. Rename files with sequential numbers
def rename_sequential(directory, base_name):
    """Rename files with sequential numbers"""
    files = [f for f in os.listdir(directory) if os.path.isfile(os.path.join(directory, f))]
    for i, filename in enumerate(files, 1):
        name, ext = os.path.splitext(filename)
        new_name = f"{base_name}_{i:03d}{ext}"
        os.rename(
            os.path.join(directory, filename),
            os.path.join(directory, new_name)
        )
        print(f" Renamed: {filename} → {new_name}")

rename_sequential(".", "doc")

# 4. Rename with preview (safe batch rename)
def preview_rename(directory, operation):
    """Preview rename operations before executing"""
    changes = []
    for filename in os.listdir(directory):
        if os.path.isfile(os.path.join(directory, filename)):
            new_name = operation(filename)
            changes.append((filename, new_name))
    
    print("📋 Preview of changes:")
    for old, new in changes[:5]:
        print(f"   {old} → {new}")
    
    confirm = input("Proceed with rename? (y/n): ")
    if confirm.lower() == 'y':
        for old, new in changes:
            os.rename(
                os.path.join(directory, old),
                os.path.join(directory, new)
            )
        print(" Rename complete!")
    else:
        print(" Canceled.")

# Test preview
preview_rename(".", lambda f: f"preview_{f}")

Batch renaming strategies:

All files — rename every file in a directory
Pattern matching — rename only files matching a pattern
Sequential — add numbers to files in order
Preview — show changes before applying
Filter — use conditions to select files

Quick Check: Why should you preview batch renames? (Answer: To avoid mistakes when renaming multiple files)

Changing File Extensions

Updating File Types

import os

# Create sample files
for ext in [".txt", ".dat", ".bak"]:
    with open(f"data{ext}", "w") as f:
        f.write(f"Sample with {ext} extension")

# 1. Change file extension for a single file
def change_extension(filename, new_extension):
    """Change a file's extension"""
    name, _ = os.path.splitext(filename)
    new_name = f"{name}{new_extension}"
    os.rename(filename, new_name)
    print(f" Renamed: {filename} → {new_name}")

change_extension("data.txt", ".csv")

# 2. Change extension for multiple files
def change_all_extensions(directory, old_ext, new_ext):
    """Change extension for all files with a specific extension"""
    for filename in os.listdir(directory):
        if filename.endswith(old_ext):
            name, _ = os.path.splitext(filename)
            new_name = f"{name}{new_ext}"
            os.rename(
                os.path.join(directory, filename),
                os.path.join(directory, new_name)
            )
            print(f" Renamed: {filename} → {new_name}")

change_all_extensions(".", ".dat", ".json")

# 3. Smart extension change with validation
def safe_extension_change(directory, old_ext, new_ext):
    """Change extension with safety checks"""
    for filename in os.listdir(directory):
        if filename.endswith(old_ext):
            old_path = os.path.join(directory, filename)
            name, _ = os.path.splitext(filename)
            new_name = f"{name}{new_ext}"
            new_path = os.path.join(directory, new_name)
            
            # Check if file already exists
            if os.path.exists(new_path):
                print(f" Skipping {filename}: {new_name} already exists")
                continue
            
            os.rename(old_path, new_path)
            print(f" Renamed: {filename} → {new_name}")

safe_extension_change(".", ".bak", ".backup")

Extension changing key points:

os.path.splitext() — splits name and extension
Check for conflicts — ensure new name doesn't exist
Batch changes — update all files with a specific extension
Validation — verify before changing

Quick Check: What function splits a filename into name and extension? (Answer: os.path.splitext())

Error Handling When Renaming

Common Rename Errors and Solutions

import os

# 1. Comprehensive rename function
def safe_rename(old_name, new_name):
    """Safely rename a file with full error handling"""
    try:
        # Check if old file exists
        if not os.path.exists(old_name):
            print(f" Error: '{old_name}' does not exist")
            return False
        
        # Check if it's a file (not a directory)
        if not os.path.isfile(old_name):
            print(f" Error: '{old_name}' is not a file")
            return False
        
        # Check if new name already exists
        if os.path.exists(new_name):
            print(f" Error: '{new_name}' already exists")
            return False
        
        # Perform the rename
        os.rename(old_name, new_name)
        print(f" Renamed: {old_name} → {new_name}")
        return True
    
    except PermissionError:
        print(f" Permission denied: Cannot rename '{old_name}'")
        return False
    
    except OSError as e:
        print(f" OS Error: {e}")
        return False
    
    except Exception as e:
        print(f" Unexpected error: {e}")
        return False

# 2. Rename with automatic backup
def rename_with_backup(old_name, new_name):
    """Rename with automatic backup of existing file"""
    if os.path.exists(new_name):
        backup_name = new_name + ".backup"
        os.rename(new_name, backup_name)
        print(f" Existing file backed up as: {backup_name}")
    
    return safe_rename(old_name, new_name)

# 3. Rename with user confirmation
def rename_with_confirm(old_name, new_name):
    """Rename with user confirmation"""
    print(f" Rename: {old_name} → {new_name}")
    response = input("Confirm? (y/n): ")
    if response.lower() == 'y':
        return safe_rename(old_name, new_name)
    else:
        print(" Canceled")
        return False

Common rename errors:

FileNotFoundError — old file doesn't exist
FileExistsError — new name already exists
PermissionError — don't have permission
IsADirectoryError — trying to rename a directory as file
Always check — before attempting rename

Quick Check: What error occurs when you try to rename a file that doesn't exist? (Answer: FileNotFoundError)

Best Practices for Renaming Files

Safe and Professional File Renaming

# Best practices for renaming files

# 1. Always check if files exist
import os

def smart_rename(old_name, new_name):
    """Smart rename with existence checks"""
    if not os.path.exists(old_name):
        print(f" File not found: {old_name}")
        return False
    
    if os.path.exists(new_name):
        print(f" File already exists: {new_name}")
        response = input("Overwrite? (y/n): ")
        if response.lower() != 'y':
            print(" Canceled")
            return False
    
    try:
        os.rename(old_name, new_name)
        print(f" Renamed: {old_name} → {new_name}")
        return True
    except Exception as e:
        print(f" Error: {e}")
        return False

# 2. Use path joining for safety
def rename_with_path(directory, old_name, new_name):
    """Rename using full paths"""
    old_path = os.path.join(directory, old_name)
    new_path = os.path.join(directory, new_name)
    return smart_rename(old_path, new_path)

# 3. Test with a dry run first
def dry_run_rename(operations):
    """Perform a dry run before actual rename"""
    print(" DRY RUN - No changes will be made:")
    for old, new in operations:
        print(f"   {old} → {new}")
    
    confirm = input("Proceed with actual rename? (y/n): ")
    if confirm.lower() == 'y':
        for old, new in operations:
            os.rename(old, new)
        print(" Rename complete!")
    else:
        print(" Canceled")

# 4. Use meaningful naming patterns
#  Good
# report_2026_08.csv
# user_profile_123.json
# data_backup_2026-08-08.txt

#  Bad
# temp.txt
# file1.txt
# new.txt

Best practices summary:

Check existence — verify file exists before renaming
Handle conflicts — deal with existing files
Use full paths — be explicit about file locations
Test first — use dry runs for batch operations
Meaningful names — use clear naming conventions

Quick Check: What is a dry run? (Answer: Testing rename operations without actually making changes)

Try It Yourself

Experiment with renaming files in the editor below. Try different patterns and operations.

Loading Pyodide... 0%

Python Code Editor

# Python Rename File - Practice

print("=" * 40)
print("RENAME FILE PRACTICE")
print("=" * 40)

import os

# Create sample files
print("\n1. CREATING SAMPLE FILES")
for i in range(3):
    with open(f"test_{i}.txt", "w") as f:
        f.write(f"Sample file {i}")
print(" Created: test_0.txt, test_1.txt, test_2.txt")

# 2. Basic rename
print("\n2. BASIC RENAME")
os.rename("test_0.txt", "renamed_0.txt")
print(" Renamed: test_0.txt → renamed_0.txt")

# 3. Adding prefix
print("\n3. ADDING PREFIX")
new_name = "prefix_" + "renamed_0.txt"
os.rename("renamed_0.txt", new_name)
print(f" Renamed: renamed_0.txt → {new_name}")

# 4. Changing extension
print("\n4. CHANGING EXTENSION")
name, ext = os.path.splitext("prefix_renamed_0.txt")
new_name = name + ".dat"
os.rename("prefix_renamed_0.txt", new_name)
print(f" Renamed: prefix_renamed_0.txt → {new_name}")

# 5. Batch rename
print("\n5. BATCH RENAME")
for i in range(1, 3):
    old = f"test_{i}.txt"
    new = f"batch_{i}.txt"
    os.rename(old, new)
    print(f" Renamed: {old} → {new}")

# 6. List final files
print("\n6. FINAL FILES")
for f in os.listdir("."):
    if f.endswith(".txt") or f.endswith(".dat"):
        print(f"   {f}")

print("\nRename file practice complete!")

========================================
RENAME FILE PRACTICE
========================================

1. CREATING SAMPLE FILES
Created: test_0.txt, test_1.txt, test_2.txt

2. BASIC RENAME
Renamed: test_0.txt → renamed_0.txt

3. ADDING PREFIX
Renamed: renamed_0.txt → prefix_renamed_0.txt

4. CHANGING EXTENSION
Renamed: prefix_renamed_0.txt → prefix_renamed_0.dat

5. BATCH RENAME
Renamed: test_1.txt → batch_1.txt
Renamed: test_2.txt → batch_2.txt

6. FINAL FILES
batch_1.txt
batch_2.txt
prefix_renamed_0.dat

Rename file practice complete!

🏆

You've Got It!

You now know how to rename files in Python. You understand os.rename(), batch renaming, and how to handle errors professionally.

Quick Quiz

Test what you've learned:

1. What function is used to rename a file in Python?

A) os.move() B) os.rename() C) os.change() D) os.update()

2. What happens if you rename a file to a name that already exists?

A) It overwrites the existing file B) It raises an error C) It creates a copy D) It asks for confirmation

3. How do you split a filename into name and extension?

A) os.path.splitname() B) os.path.splitext() C) os.path.split() D) os.path.divide()

4. What is a dry run when renaming files?

A) Renaming files quickly B) Renaming files in a different directory C) Testing rename operations without making changes D) Renaming files with a pattern

5. Which of these is a best practice for renaming files?

A) Always rename without checking B) Never use os.path C) Ignore errors D) Check if the file exists before renaming

Frequently Asked Questions

What is the difference between os.rename() and shutil.move()?

os.rename() renames a file within the same directory or moves it to a different directory. shutil.move() is more flexible and can move files across different file systems. For simple renaming, os.rename() is sufficient.

Can I rename a file to a different directory?

Yes! os.rename() can move and rename files simultaneously if you provide a full path for the new name: os.rename("file.txt", "archive/file.txt"). This effectively moves the file to the archive directory.

What happens if I try to rename a file that doesn't exist?

Python will raise a FileNotFoundError. Always check if a file exists using os.path.exists() before attempting to rename it.

What's a common interview question about file renaming?

Common questions include: "How do you rename a file in Python?" "What is the difference between os.rename() and shutil.move()?" and "How would you rename multiple files in a directory?"

Can I undo a rename operation?

No, renaming is permanent. That's why it's important to use dry runs, backups, and error handling when renaming files, especially in batch operations.

How do I rename files based on their content?

First read the file content, extract the information you need, then use that information to construct the new filename. For example, you could read a CSV file and rename it based on a value in the first row.

Where to Go From Here

Now that you can rename files, check out these related topics:

Previous: Write to File Next: Copy File →

Python

Python: Rename File

Renaming Files in Python

Using os.rename()

The Primary Way to Rename Files

Renaming with Patterns

Adding Prefixes, Suffixes, and More

Batch Renaming Files

Renaming Multiple Files at Once

Changing File Extensions

Updating File Types

Error Handling When Renaming

Common Rename Errors and Solutions

Best Practices for Renaming Files

Safe and Professional File Renaming

Try It Yourself

You've Got It!

Quick Quiz

Frequently Asked Questions

What is the difference between os.rename() and shutil.move()?

Can I rename a file to a different directory?

What happens if I try to rename a file that doesn't exist?

What's a common interview question about file renaming?

Can I undo a rename operation?

How do I rename files based on their content?

Where to Go From Here

Copy File

Move File

List Files in Directory

Python

Python: Rename File

Renaming Files in Python

Using os.rename()

The Primary Way to Rename Files

Renaming with Patterns

Adding Prefixes, Suffixes, and More

Batch Renaming Files

Renaming Multiple Files at Once

Changing File Extensions

Updating File Types

Error Handling When Renaming

Common Rename Errors and Solutions

Best Practices for Renaming Files

Safe and Professional File Renaming

Try It Yourself

You've Got It!

Quick Quiz

Frequently Asked Questions

What is the difference between os.rename() and shutil.move()? ▼

Can I rename a file to a different directory? ▼

What happens if I try to rename a file that doesn't exist? ▼

What's a common interview question about file renaming? ▼

Can I undo a rename operation? ▼

How do I rename files based on their content? ▼

Where to Go From Here

Copy File

Move File

List Files in Directory

What is the difference between os.rename() and shutil.move()?

Can I rename a file to a different directory?

What happens if I try to rename a file that doesn't exist?

What's a common interview question about file renaming?

Can I undo a rename operation?

How do I rename files based on their content?