def _clean_join_predicates(left, right, predicates):
import ibis.expr.analysis as L
result = []
for pred in predicates:
if isinstance(pred, tuple):
if len(pred) != 2:
raise com.ExpressionError('Join key tuple must be ' 'length 2')
lk, rk = pred
lk = left._ensure_expr(lk)
rk = right._ensure_expr(rk)
pred = lk == rk
elif isinstance(pred, str):
pred = left[pred] == right[pred]
elif not isinstance(pred, ir.Expr):
raise NotImplementedError
if not isinstance(pred, ir.BooleanColumn):
raise com.ExpressionError('Join predicate must be comparison')
preds = L.flatten_predicate(pred)
result.extend(preds)
_validate_join_predicates(left, right, result)
return tuple(result)
def to_array(self) -> ir.Column:
"""View a single column table as an array.
Returns
-------
Value
A single column view of a table
"""
from ibis.expr import operations as ops
schema = self.schema()
if len(schema) != 1:
raise com.ExpressionError(
'Table must have exactly one column when viewed as array'
)
return ops.TableArrayView(self).to_expr()
def __len__(self):
raise com.ExpressionError('Use .count() instead')
