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ast.Lambda

functions and classes

The node for a lambda expression: args is an arguments node, body a single expression (not a list of statements); the node has no name.

Syntax

ast.Lambda(args, body)

The body is exactly one expression, so a Lambda has no return: the result is body itself. 'f = lambda x: x' is an Assign with a Lambda in value, and the name f is not attached to the node: tools listing functions via FunctionDef skip such ones. Parameters work as in def: the same arguments node with defaults.

Examples

import ast
a = ast.parse('f = lambda x, y=2: x * y').body[0]
lam = a.value
print(type(a).__name__, type(lam).__name__)  # → Assign Lambda
print([p.arg for p in lam.args.args], type(lam.body).__name__)  # → ['x', 'y'] BinOp

See also

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