Client APIs
Common Operations
The Expression class also contains many operations that can be applied to any Expression type.  
| Operation                      | Description                                                                                                    |
|--------------------------------|----------------------------------------------------------------------------------------------------------------|
| `.alias(name: str)`            | Applies an alias to the expression.                                                                            |
| `.cast(type: DuckDBPyType)`    | Applies a cast to the provided type on the expression.                                                         |
| `.isin(*exprs: Expression)`    | Creates an [`IN` expression](#docs:sql:expressions:in::in) against the provided expressions as the list.        |
| `.isnotin(*exprs: Expression)` | Creates a [`NOT IN` expression](#docs:sql:expressions:in::not-in) against the provided expressions as the list. |
| `.isnotnull()`                 | Checks whether the expression is not `NULL`.                                                                   |
| `.isnull()`                    | Checks whether the expression is `NULL`.                                                                       |  
#### Order Operations {#docs:api:python:expression::order-operations}  
When expressions are provided to `DuckDBPyRelation.order()`, the following order operations can be applied.  
| Operation                      | Description                                                                                                    |
|--------------------------------|----------------------------------------------------------------------------------------------------------------|
| `.asc()`                       | Indicates that this expression should be sorted in ascending order.                                            |
| `.desc()`                      | Indicates that this expression should be sorted in descending order.                                           |
| `.nulls_first()`               | Indicates that the nulls in this expression should precede the non-null values.                                |
| `.nulls_last()`                | Indicates that the nulls in this expression should come after the non-null values.                             |