Skip to main content
This is a pre-production deployment of Warehouse. Changes made here affect the production instance of PyPI (
Help us improve Python packaging - Donate today!

Syntax changes for python lambdas.

Project Description

Supports Python 2.6 - 3.5

What is this?

A better python lambda syntax for your anonymous function needs.

Write a = (x) > x instead of a = lambda x: x. See below for syntax caveats.

Get started immediately: pip install lambdazen

from lambdazen import zen
def otherfunc(*args):
    print sum(args)

# The zen decorator allows you to define lambdas with a better syntax
def example():
    example.epic = (x, y, z) > otherfunc(x, y, z)

    # Multiline lambdas are a tuple or list of statements
    # The assignment operator inside is << instead of =
    # The last statement is the return value
    example.multiline = (x, y, z) > (
        s << otherfunc(x, y, z),

# Call function so the lambdas are bound to function attributes

>>> 6

>>> 6


  • better lambdas can only be defined in a function with the @zen attribute
  • any other code in this function will be executed, it’s best to use the function as a container of lambdas

How does it work

Read the story

TLDR; Runtime in-memory source rewriting and recompilation

Additional Examples

from lambdazen import zen

# Lambdas don't need to be bound to the function
def normalizeString(nS):
    transforms = [
        (s) > s.strip(),
        (s) > s.lower(),
        (s) > s.replace(' ', '_')]

    apply_all = (transforms_list, s) > (
        is_done << (len(transforms_list) == 0),
        current_transform << transforms_list[0] if not is_done else None,
        remaining_transforms << transforms_list[1:] if not is_done else None,
        current_transform(apply_all(remaining_transforms, s)) if not is_done else s)

    return apply_all(transforms, nS)

normalizeString("Abraham Lincoln")
>>> "abraham_lincoln"

Release History

This version
History Node


History Node


History Node


History Node


History Node


History Node


History Node


Download Files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Filename, Size & Hash SHA256 Hash Help File Type Python Version Upload Date
(3.8 kB) Copy SHA256 Hash SHA256
Source None Sep 18, 2016

Supported By

Elastic Elastic Search Pingdom Pingdom Monitoring Dyn Dyn DNS Sentry Sentry Error Logging CloudAMQP CloudAMQP RabbitMQ Heroku Heroku PaaS Kabu Creative Kabu Creative UX & Design Fastly Fastly CDN DigiCert DigiCert EV Certificate Google Google Cloud Servers DreamHost DreamHost Log Hosting