NameError: name '__file__' is not defined in Python [Fixed]

# NameError: name '__file__' is not defined' in Python

The "NameError: name '__file__' is not defined'" occurs when we use the __file__ global variable in an interactive shell.

To solve the error, create a Python script and run the script with the python script_name.py command instead.

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Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name '__file__' is not defined. Did you mean: '__name__'?

# Trying to access the __file__ variable in an interactive shell

The most common cause of the error is trying to access the __file__ global variable in an interactive shell.

If you need to access the variable in an interactive shell, try the following code sample.

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import os

# 👇️ '/home/borislav/Desktop/bobbyhadz_python'
os.path.dirname(os.path.abspath('__file__'))

The os.path.abspath method takes a path and returns a normalized, absolute version of the path.

# Storing your code in a Python module instead

However, a much better approach is to store your code in a Python module.

Create a file named main.py and add the following code to the file.

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import os

result = os.path.join(os.path.dirname(__file__))

# 👇️ /home/borislav/Desktop/bobbyhadz_python
print(result)

Now you can run your code with the python main.py command instead of using the interactive shell.

You can exit the interactive shell with the exit() function.

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exit()

Now run your Python module with the python main.py command.

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python main.py

# 👇️ For Python 3
python3 main.py

# 👇️ Using py alias (Windows)
py main.py

When you load a module in Python, the global __file__ variable is set to its path.

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import os


# 👇️ /home/borislav/Desktop/bobbyhadz_python/main.py
print(__file__)

# 👇️ /home/borislav/Desktop/bobbyhadz_python
print(os.path.dirname(__file__))

# 👇️ /home/borislav/Desktop/bobbyhadz_python/another.py
print(os.path.join(os.path.dirname(__file__), 'another.py'))

The os.path.dirname method returns the directory component of a pathname.

The os.path.join method joins one or more paths intelligently.

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import os

# 👇️ /home/bobbyhadz
print(os.path.join('/', 'home', 'bobbyhadz'))

The method concatenates the provided paths with exactly one directory separator following each non-empty part except the last.

If any of the provided components is an absolute path, all previous components are thrown away and joining continues from the absolute path onwards.

# Using the inspect module instead

An alternative approach is to use the inspect module to get the path to the current file.

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import inspect

file_path = inspect.getfile(lambda: None)

# 👇️ /home/borislav/Desktop/bobbyhadz_python/main.py
print(file_path)

The inspect.getfile() method returns the absolute path to the module in which the lambda function is defined.

In other words, it returns the absolute path to the current module.

# Getting the current working directory with os.getcwd()

You can use the os.getcwd() method if you need to get the current working directory.

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import os

# 👇️ '/home/borislav/Desktop/bobbyhadz_python'
print(os.getcwd())

# Getting the name of the module with sys.argv

If you need just the name of the current module, use the sys.argv list.

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import sys

print(sys.argv[0])  # 👉️ main.py

The sys.argv list contains the command line arguments that were passed to the Python script.

# Accessing the attribute on imported modules

The __file__ attribute is also available on modules you import into your Python script (e.g. main.py).

For example, here is a file called another.py that imports the main module and makes use of its __file__ attribute.

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import main

# 👇️ /home/borislav/Desktop/bobbyhadz_python/main.py
print(main.__file__)

Another example would be to install a third-party module.

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pip install transformers
pip3 install transformers

Now I can import the transformers module and access its __file__ attribute to get the path to the file where the module is stored.

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import transformers

# 👇️ /home/borislav/Desktop/bobbyhadz_python/venv/lib/python3.10/site-packages/transformers/__init__.py
print(transformers.__file__)