TestNG vs Lettuce comparison of testing frameworks
What are the differences between TestNG and Lettuce?

TestNG

https://testng.org/doc/documentation-main.html

Lettuce

https://pypi.org/project/lettuce/
Programming language

Java

Python

Category

Unit Testing, Intergration Testing, End-to-End Testing

Unit Testing, Acceptance Testing

General info

TestNG is a testing framework for the Java programming language inspired by JUnit and NUnit

TestNG is similar to JUnit and NUnit but with newer functionalities such as: annotations, test that your code is multithread safe, flexible test configuration, support for data-driven testing (with @DataProvider), support for parameters, powerful execution model (no more TestSuite) and more... It's also designed to cover all categories of tests unit, functional, end-to-end, intergration... etc

Lettuce is a BDD testing tool for Python

Lettuce is a testing tool for Python which is inspired by Ruby's Cucumber that supports Gherkin. It can execute plain-text functional descriptions as automated tests for Python projects just like Cucumber does for Ruby
xUnit
Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.

No

No

However It can generate xml results for behaviour tests xUnit style
Client-side
Allows testing code execution on the client, such as a web browser

Yes

The scope of testing with testNg is wide and you can test various front-end functionalities and behaviours with it

Yes

By integrating Lettuce with Selenium’s Python bindings, you have a robust framework for testing Django applications. It can test front-end behaviour
Server-side
Allows testing the bahovior of a server-side code

Yes

You can test server-side functionalities and behaviours with TestNg

Yes

Lettuce can test various server and database behaviours and interactions
Fixtures
Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test

Yes

Fixtures are inbuilt into testNG, these are the annotations which are: @BeforeSuite, @AfterSuite, @BeforeTest, @AfterTest, @BeforeGroups, @AfterGroups, @BeforeClass, @AfterClass, @BeforeMethod, @AfterMethod

N/A

Group fixtures
Allows defining a fixed, specific states of data for a group of tests (group-fixtures). This ensures specific environment for a given group of tests.

Yes

You can use various fixtures to setup environments for group tests

N/A

Generators
Supports data generators for tests. Data generators generate input data for test. The test is then run for each input data produced in this way.

N/A

Yes

By using a third party library
Licence
Licence type governing the use and redistribution of the software

Apache License 2.0

Unknown

Mocks
Mocks are objects that simulate the behavior of real objects. Using mocks allows testing some part of the code in isolation (with other parts mocked when needed)

Yes

By Use of an external library like mockit which intergrates well with testNG

By adding the lettuce-tools library one has access to the Mock module to implement a configurable http REST mock.
Grouping
Allows organizing tests in groups

Yes

Multiple test cases can be grouped more easily by converting them into testng.xml file, in which you can make priorities which test case should be executed first

Yes

It allows grouping of tests
Other
Other useful information about the testing framework