def cross_join(*args, **kwargs):
"""
Perform a cross join (cartesian product) amongst a list of tables, with
optional set of prefixes to apply to overlapping column names
Parameters
----------
positional args: tables to join
prefixes keyword : prefixes for each table
Not yet implemented
Examples
--------
>>> joined1 = ibis.cross_join(a, b, c, d, e)
>>> joined2 = ibis.cross_join(a, b, c, prefixes=['a_', 'b_', 'c_']))
Returns
-------
joined : TableExpr
If prefixes not provided, the result schema is not yet materialized
"""
op = _ops.CrossJoin(*args, **kwargs)
return TableExpr(op)
def cross_join(
left: TableExpr,
right: TableExpr,
*rest: TableExpr,
suffixes: tuple[str, str] = ("_x", "_y"),
) -> TableExpr:
"""Compute the cross join of a sequence of tables.
Parameters
----------
left
Left table
right
Right table
rest
Additional tables to cross join
suffixes
Left and right suffixes that will be used to rename overlapping
columns.
Returns
-------
TableExpr
Cross join of `left`, `right` and `rest`
Examples
--------
>>> import ibis
>>> schemas = [(name, 'int64') for name in 'abcde']
>>> a, b, c, d, e = [
... ibis.table([(name, type)], name=name) for name, type in schemas
... ]
>>> joined1 = ibis.cross_join(a, b, c, d, e)
>>> joined1
r0 := UnboundTable[e]
e int64
r1 := UnboundTable[d]
d int64
r2 := UnboundTable[c]
c int64
r3 := UnboundTable[b]
b int64
r4 := UnboundTable[a]
a int64
r5 := CrossJoin[r3, r2]
r6 := CrossJoin[r5, r1]
r7 := CrossJoin[r6, r0]
CrossJoin[r4, r7]
"""
from .. import operations as ops
expr = ops.CrossJoin(
left,
functools.reduce(TableExpr.cross_join, rest, right),
[],
).to_expr()
return ops.relations._dedup_join_columns(
expr,
left=left,
right=right,
suffixes=suffixes,
)
def cross_join(left, right, prefixes=None):
"""
"""
op = _ops.CrossJoin(left, right)
return TableExpr(op)