unopt: Utility functions to unwrap Optional[T]

Overview

unopt provides several utility functions to "unwrap" the Optional[T] (or T | None) objects: removes the Optional type hint and obtains the underlying object.

unopt functions are inspired by the Rust's Option<T> functionality, but the behavior is tuned to Python's convention. E.g., unwrap() raises an exception instead of aborting.

Install

pip install unopt

Examples

from unopt import *

foo: Optional[int] = 123
bar: Optional[int] = None

# unwrap() returns the given object if it is not None.
assert unwrap(foo) == 123
unwrap(bar)  # Raises UnwrapError

# unwrap_or() returns the default value if the given object is None.
assert unwrap_or(foo, 456) == 123
assert unwrap_or(bar, 456) == 456

# unwrap_or_else() returns the default value obtained by invoking the given function.
assert unwrap_or_else(foo, lambda: 456) == 123
assert unwrap_or_else(bar, lambda: 456) == 456

# unwrap_unchecked() just casts the given object without value checking.
assert unwrap_unchecked(foo) == 123
assert unwrap_unchecked(bar) is None  # Unsafe