pyaccesskit.schema.expressions¶

pyaccesskit.schema.expressions ¶

Access expression literals: rendering Python values and parsing them back.

Access stores properties such as DefaultValue as expression text. A classic mistake is setting a text default to Unknown instead of "Unknown" (Access then looks for a field or function called Unknown). PyAccessKit takes Python values and renders the right literal; raw expressions are passed with :class:Expr::

Column.text("Status", default="Unknown")          # stored as  "Unknown"
Column.date_time("CreatedAt", default=Expr("Now()"))
Column.currency("Total", default=0)                # stored as  0

DefaultValue `module-attribute` ¶

DefaultValue = (
    Expr
    | bool
    | int
    | float
    | Decimal
    | datetime
    | date
    | time
    | str
)

Types accepted as a column default: a Python literal or an :class:Expr.

Expr `dataclass` ¶

Expr(expr: str)

A raw Access expression, passed through verbatim (e.g. Expr("Now()"), Expr("[Qty]*2")).

render_literal ¶

render_literal(value: DefaultValue) -> str

Render a Python value as Access expression text.

Raises:

Type	Description
`SpecError`	For values Access cannot represent (NaN, time-zone aware datetimes...).

parse_literal ¶

parse_literal(text: str | None) -> DefaultValue | None

Parse Access expression text into a Python literal, or an :class:Expr if it is not a literal.

Returns None for empty text. Understands quoted strings, numbers, True/False/Yes/No/ On/Off and #date# literals (ISO or US m/d/yyyy order).

pyaccesskit.schema.expressions¶