xlineparse

Python library to parse variable length delimited lines.

Usage

pip install xlineparse

import datetime as dt
from decimal import Decimal
from typing import Annotated, Literal

import xlineparse as xlp

FooLine = tuple[
    Literal["foo"],
    int,
    Decimal,
    Decimal | None,
    Annotated[bool, xlp.BoolField(true_value="Y", false_value="F")],
    Annotated[dt.date, xlp.DateField(format="%Y-%m-%d")],
    Annotated[dt.time, xlp.TimeField(format="%H%M%s")],
]
BarLine = tuple[
    Literal["bar"],
    int,
]
schema = xlp.Schema.from_type(
    delimiter="|",
    quote_str=None,
    trailing_delimiter=False,
    lines=FooLine | BarLine,
)

schema.parse_line("foo|1|3.14||Y|2012-01-02|123200")

#  Will return:

(
    "foo",
    1,
    Decimal("3.14"),
    None,
    True,
    dt.date(2012, 1, 2),
    dt.time(12, 32, 0),
)

Or directly construct Fields:

schema = xlp.Schema(
    delimiter="|",
    quote_str=None,
    trailing_delimiter=False,
    lines=[
        xlp.Line(
            name="a",
            fields=[
                xlp.DecimalField(
                    required=True,
                    round_decimal_places=None,
                    min_value=Decimal("2.0"),
                    max_value=None,
                )
            ],
        )
    ],
)
assert schema.parse_line("a|2.0")

#  Will return:

("a", Decimal("2.0"))

TODO:

• Maybe the big decimals are just floats?
• Allow delimiters to be escaped.
• Can we make enums quicker by moving to Rust?

Install/Develop

uv pip install -e '.[dev]'
maturin develop

Make release

• Add pypi token and user = __token__ to settings (do this once).
• Upversion pyproject.toml.

git tag -a v0.0.x head -m v0.0.x
git push origin v0.0.x