cycquery.ops.AddColumn

class AddColumn(add_to, col, negative=False, new_col_labels=None)

Bases: QueryOp

Add a column to some columns.

Parameters:

• add_to (Union[str, List[str]]) – Column names specifying to which columns is being added.

• col (str) – Column name of column to add to the add_to columns.

• negative (Optional[bool]) – Subtract the column rather than adding.

• new_col_labels (Union[str, List[str], None]) – If specified, create new columns with these labels. Otherwise, apply the function to the existing columns.

Examples

>>> AddColumn("col1", "col2")(table)
>>> AddColumn(["col1", "col2"], "col3")(table)
>>> AddColumn("col1", "col2", negative=True)(table)
>>> AddColumn("col1", "col2", "col1_plus_col2")(table)
>>> AddColumn(["col1", "col2"], "col3", ["col1_plus_col3", "col2_plus_col3"])(table)

Warning

Pay attention to column types. Some combinations will work, whereas others will not.

Initialize the operation.

Methods

__call__(table)

Process the table.

Parameters:

table (Union[Select, Subquery, Table, DBTable]) – Table on which to perform the operation.

Returns:

Processed table.

Return type:

sqlalchemy.sql.selectable.Subquery

__init__(add_to, col, negative=False, new_col_labels=None)

Initialize the operation.