python-nameof 1.2.2

A Python implementation of the C# nameof operator.

python-nameof: a Python implementation of C# nameof operator

This is a follow-up to this project since the author archived it, preferring the varname library which used to cover nameof, but then varname deprecated it.

A Python utility that mimics the C# nameof operator, allowing you to get variable, attribute, or property names as strings at runtime.

It is an essential operator to allow flexible and reliable refactoring, among many other things.

This implementation supports string interpolation, so it's easy to reference variable names when logging, e.g.
log.error(f"{nameof(somevariable)} is incorrect").

Installation

Pip:

pip install python-nameof

My recommendation is to always use uv instead of pip – I personally think it's the best package and environment manager for Python.

uv add python-nameof

Usage

Import:

from nameof import nameof

Simple usage:

foo = 123
print(nameof(foo))  # Output: 'foo'

It supports string interpolation, so it's easier to reference variable names when logging, allowing for easier refactoring.
In the example below, refactoring the name of second_param will propagate to the printed message without having to manually do it.

def myFuncWithAmazingLogging(first_param: int):
    valid_threshold = 10
    if first_param < 10:
        print(f"The parameter {nameof(first_param)} should be less than {valid_threshold}")

It works for class attributes and instance variables.

class Bar:
    attr = 99
bar = Bar()
print(nameof(Bar.attr))      # Output: 'attr'
print(nameof(bar.attr))      # Output: 'attr'

It works also for nested classes.

class Inner:
    @property
    def value(self):
        return 10

class Outer:
    def __init__(self):
        self.inner = Inner()

outer = Outer()
print(nameof(outer.inner.value))  # Output: 'value'

Multiple assignments

If a variable is assigned twice, only the first name is returned.

a = b = 1

nameof(a) # returns "a"
nameof(b) # returns "b"

nameof(1) # raises ValueError (see next section below)

Error Handling

If you pass a value or an expression that is not a variable or attribute, nameof raises a ValueError:

nameof(42)            # Raises ValueError
nameof("foo.bar")     # Raises ValueError
nameof("nameof(bar)") # Raises ValueError