🔍 v6e

A simple, type-safe, and extensible Python parsing and validation framework

Why the name?

v6e comes from the numeronym of "validate".

Usage

import v6e as v

my_parser = v.int().gte(18).lte(21)

# Use it only to check if the value conforms
my_parser.check(18)  # True
my_parser.check(21)  # True
my_parser.check(54)  # False

# Use `.parse()` (or call it) to validate and get the parsed value
my_parser.parse(21)  # Ok -> Returns 21 (int)
my_parser.parse("21")  # Ok -> Returns 21 (int)
my_parser.parse(54)  # Err -> Raises a ParseException
my_parser(54)  # Err -> Raises a ParseException

v6e also supports custom parsers, custom reusable types, unions of parsers, and more. See more in our docs!

Examples

Check out the examples in ./examples! You can run them locally with:

uv run examples/parsers.py

🐍 Type-checking

This library is fully type-checked. This means that all types will be correctly inferred from the arguments you pass in.

In this example your editor will correctly infer the type:

my_parser = v.int().gte(8).lte(4)
t.reveal_type(my_parser)  # Type of "my_parser" is "V6eInt"
t.reveal_type(my_parser.check)  # Type of "my_parser.check" is "(raw: Any) -> bool"
t.reveal_type(my_parser.safe_parse)  # Type of "my_parser" is "(raw: Any) -> V6eResult[int]"
t.reveal_type(my_parser.parse)  # Type of "my_parser" is "(raw: Any) -> int"
t.reveal_type(my_parser.__call__)  # Type of "my_parser" is "(raw: Any) -> int"

Why should I care?

Type checking will help you catch issues way earlier in the development cycle. It will also provide nice autocomplete features in your editor that will make you faster ⚡.

Alpha notice

This project is still in its alpha phase. Expect frequent and breaking changes. You can see more in our planned work doc.