CodeQL library for Python
codeql/python-all 1.0.1 (changelog, source)

Member predicate Function::isLambda

Holds if this function represents a lambda.

The extractor reifies each lambda expression as a (local) function with the name “lambda”. As lambda is a keyword in Python, it’s impossible to create a function with this name otherwise, and so it’s impossible to get a non-lambda function accidentally classified as a lambda.

predicate isLambda()