Skip to main content

Documentation Index

Fetch the complete documentation index at: https://docs.pixeltable.com/llms.txt

Use this file to discover all available pages before exploring further.

​
class  pixeltable.exprs.Expr

A Pixeltable expression. All Pixeltable expressions, including column references (such as t.col), UDF calls (t.my_string.lower()), and compound expressions (t.col + 5) are instances of this class. Not thread-safe: Expr and subclasses contain execution state and are never thread-safe.

​
method  astype()

Signature
astype(new_type: ts.ColumnType | type | _AnnotatedAlias) -> exprs.TypeCast
Return a new expression that casts this expression to a different type. This represents a type cast, not a type coercion, so it will not mutate the underlying data; it simply changes the static type given by the expression. Parameters:
  • new_type (ts.ColumnType | type | _AnnotatedAlias): The type to cast to.
Examples: Given an existing column t.json_col of type pxt.Json, cast that column to type pxt.String: 
t.json_col.astype(pxt.String)
This will assume that all values in t.json_col are actually strings, and it will result in an error at runtime if there are values in t.json_col that are not strings. It will not convert those values to a string representation. (For that, use the [dumps()][pixeltable.functions.json.dumps] UDF instead.)

​
method  isin()

Signature
isin(value_set: Any) -> exprs.InPredicate
Return a new, boolean-valued expression that is True whenever this expression is in value_set. Parameters:
  • value_set (Any): Either another expression that evaluates to a set of values, or a constant collection of values. If the latter, can be any Iterable.
Examples: These examples assume that t is a table with a column int_col of type pxt.Int, and another column list_col of type pxt.Json, containing lists of integers. Select all rows where int_col is in the constant set {1, 3, 22}: 
t.where(t.int_col.isin({1, 3, 22})).select()
Select all rows where int_col is in the set of values in that row’s list_col: 
t.where(t.int_col.isin(t.list_col)).select()
Last modified on May 9, 2026