def param(type):
"""Create a parameter of a particular type to be defined just before
execution.
Parameters
----------
type : dt.DataType
The type of the unbound parameter, e.g., double, int64, date, etc.
Returns
-------
ScalarExpr
Examples
--------
>>> import ibis
>>> import ibis.expr.datatypes as dt
>>> start = ibis.param(dt.date)
>>> end = ibis.param(dt.date)
>>> schema = [('timestamp_col', 'timestamp'), ('value', 'double')]
>>> t = ibis.table(schema)
>>> predicates = [t.timestamp_col >= start, t.timestamp_col <= end]
>>> expr = t.filter(predicates).value.sum()
"""
import ibis.expr.datatypes as dt
import ibis.expr.operations as ops
return ops.ScalarParameter(dt.dtype(type)).to_expr()
def param(type: dt.DataType) -> ir.ScalarExpr:
"""Create a deferred parameter of a given type.
Parameters
----------
type
The type of the unbound parameter, e.g., double, int64, date, etc.
Returns
-------
ScalarExpr
A scalar expression backend by a parameter
Examples
--------
>>> import ibis
>>> import ibis.expr.datatypes as dt
>>> start = ibis.param(dt.date)
>>> end = ibis.param(dt.date)
>>> schema = [('timestamp_col', 'timestamp'), ('value', 'double')]
>>> t = ibis.table(schema)
>>> predicates = [t.timestamp_col >= start, t.timestamp_col <= end]
>>> expr = t.filter(predicates).value.sum()
"""
return ops.ScalarParameter(dt.dtype(type)).to_expr()
