FileNotFoundError in Python — How to Fix It

You tried to open a file in Python and got “FileNotFoundError: No such file or directory”?

This error means Python can’t find the file at the path (location) you specified. It could be a typo in the file name, or the file might be in a different folder than Python is looking in.

Don’t worry, this is a very common issue. Once you understand how file paths work, you’ll fix it in no time.

Why FileNotFoundError happens in Python

Python raises FileNotFoundError when it can’t locate a file. The usual causes are:

• Wrong file name or typo: The file name in your code doesn’t match the actual file name (including the extension)
• Wrong directory: Python is looking in a different folder than where the file actually is
• The file doesn’t exist: The file hasn’t been created yet, or was moved or deleted

Solution 1: Check the file name and path (most common fix)

Most FileNotFoundErrors come from a simple mismatch between the path in your code and the actual file location.

1. Read the error message carefully

# Example error
FileNotFoundError: [Errno 2] No such file or directory: 'data.csv'
# → Python is looking for "data.csv" but can't find it

The file name at the end of the error is exactly what Python searched for.

2. Double-check the file name, including the extension

# ✗ Common mistakes
open("data.csv")    # File is actually named "Data.csv" (capital D)
open("data.csv")    # File is actually "data.CSV" (uppercase extension)
open("data")        # Missing the .csv extension

# ✓ Make sure the name matches exactly
open("Data.csv")

File names are case-sensitive on Mac and Linux (though not on Windows). Always match the exact name.

3. Check where Python is running from

# Add this to your code to see Python's current working directory
import os
print(os.getcwd())

If the file is in a different folder than what os.getcwd() shows, that’s the problem. See Solution 2 for how to fix it.

Solution 2: Use the correct file path

If the file exists but is in a different folder, you need to tell Python the full path.

1. Use an absolute path (the full address)

On Windows:

# Use the full path with raw string (r"...") to avoid backslash issues
file = open(r"C:\Users\YourName\Documents\data.csv")

On Mac:

# Mac uses forward slashes
file = open("/Users/YourName/Documents/data.csv")

If the file opens without errors, you’ve got the right path.

2. Or use a path relative to your script’s location

import os

# Get the directory where your script is located
script_dir = os.path.dirname(os.path.abspath(__file__))

# Build the path to the file relative to your script
file_path = os.path.join(script_dir, "data.csv")

file = open(file_path)

This approach works regardless of where you run the script from, because it always starts from the script’s own folder.

3. Verify the file exists before opening

import os

file_path = "data.csv"
if os.path.exists(file_path):
    file = open(file_path)
    print("File opened successfully")
else:
    print(f"File not found: {os.path.abspath(file_path)}")
    # This prints the full path Python is looking at

The os.path.abspath() output shows you exactly where Python is looking. Compare that with the file’s actual location.

Solution 3: Fix common path mistakes on Windows

Windows file paths have a few quirks that trip up beginners.

1. Backslash problems

# ✗ Backslashes are treated as escape characters
open("C:\Users\new_file\data.csv")  # \n and \d are escape sequences!

# ✓ Option A: Use raw strings (prefix with r)
open(r"C:\Users\new_file\data.csv")

# ✓ Option B: Use forward slashes (works on Windows too)
open("C:/Users/new_file/data.csv")

# ✓ Option C: Use double backslashes
open("C:\\Users\\new_file\\data.csv")

2. Spaces in file paths

# Spaces in folder names are fine — just include them in the string
open(r"C:\Users\Your Name\My Documents\data.csv")

As long as the path is inside quotes, spaces work normally.

If nothing works

If you still can’t get the file to open:

• List all files in the directory: This confirms what files Python can actually see

import os

# List all files in the current directory
for filename in os.listdir("."):
    print(filename)

• Check file permissions: On Mac or Linux, the file might exist but Python might not have permission to read it. Use ls -la in the terminal to check
• Tip for asking for help: Include the full error message, the path you’re using, and the output of os.getcwd(). This helps others pinpoint the issue

Summary

• FileNotFoundError means the file path in your code doesn’t match the actual file location — check for typos, including the file extension
• Use os.getcwd() to see where Python is looking, and use absolute paths or os.path.join() for reliable paths
• On Windows, use raw strings (r"...") or forward slashes to avoid backslash escape issues

Related articles:

• name-error-not-defined.html (NameError: name is not defined — how to fix)
• type-error-python.html (How to fix TypeError in Python)
• syntax-error-invalid-syntax.html (SyntaxError: invalid syntax — causes and fixes)