PyBrain is a modular Machine Learning Library for Python. Its goal is to offer flexible, easy-to-use yet still powerful algorithms for Machine Learning Tasks and a variety of predefined environments to test and compare your algorithms.

PyBrain is short for Python-Based Reinforcement Learning, Artificial Intelligence and Neural Network Library. In fact, we came up with the name first and later reverse-engineered this quite descriptive “Backronym”.

“PyBrain(Python-Based Reinforcement Learning, Artificial Intelligence and Neural Network)是Python的一个机器学习模块，它的目标是为机器学习任务提供灵活、易应、强大的机器学习算法。（这名字很霸气）

PyBrain正如其名，包括神经网络、强化学习(及二者结合)、无监督学习、进化算法。因为目前的许多问题需要处理连续态和行为空间，必须使用函数逼近(如神经网络)以应对高维数据。PyBrain以神经网络为核心，所有的训练方法都以神经网络为一个实例。”

官方主页：

6. PyML – machine learning in Python

PyML is an interactive object oriented framework for machine learning written in Python. PyML focuses on SVMs and other kernel methods. It is supported on Linux and Mac OS X.

“PyML是一个Python机器学习工具包，为各分类和回归方法提供灵活的架构。它主要提供特征选择、模型选择、组合分类器、分类评估等功能。”

项目主页：

7. Milk：Machine learning toolkit in Python.

Its focus is on supervised classification with several classifiers available:
SVMs (based on libsvm), k-NN, random forests, decision trees. It also performs
feature selection. These classifiers can be combined in many ways to form
different classification systems.

“Milk是Python的一个机器学习工具箱，其重点是提供监督分类法与几种有效的分类分析：SVMs(基于libsvm)，K-NN，随机森林经济和决策树。它还可以进行特征选择。这些分类可以在许多方面相结合，形成不同的分类系统。对于无监督学习，它提供K-means和affinity propagation聚类算法。”

官方主页：

8. PyMVPA: MultiVariate Pattern Analysis (MVPA) in Python

PyMVPA is a Python package intended to ease statistical learning analyses of large datasets. It offers an extensible framework with a high-level interface to a broad range of algorithms for classification, regression, feature selection, data import and export. It is designed to integrate well with related software packages, such as scikit-learn, and MDP. While it is not limited to the neuroimaging domain, it is eminently suited for such datasets. PyMVPA is free software and requires nothing but free-software to run.

“PyMVPA(Multivariate Pattern Analysis in Python)是为大数据集提供统计学习分析的Python工具包，它提供了一个灵活可扩展的框架。它提供的功能有分类、回归、特征选择、数据导入导出、可视化等”

官方主页：

9. Pyrallel – Parallel Data Analytics in Python

Experimental project to investigate distributed computation patterns for machine learning and other semi-interactive data analytics tasks.

“Pyrallel(Parallel Data Analytics in Python)基于分布式计算模式的机器学习和半交互式的试验项目，可在小型集群上运行”

Github代码页：

10. Monte – gradient based learning in Python

Monte (python) is a Python framework for building gradient based learning machines, like neural networks, conditional random fields, logistic regression, etc. Monte contains modules (that hold parameters, a cost-function and a gradient-function) and trainers (that can adapt a module’s parameters by minimizing its cost-function on training data).

Modules are usually composed of other modules, which can in turn contain other modules, etc. Gradients of decomposable systems like these can be computed with back-propagation.

“Monte (machine learning in pure Python)是一个纯Python机器学习库。它可以迅速构建神经网络、条件随机场、逻辑回归等模型，使用inline-C优化，极易使用和扩展。”

官方主页：

11. Theano

Theano is a Python library that allows you to define, optimize, and evaluate mathematical expressions involving multi-dimensional arrays efficiently. Theano features:
1）tight integration with NumPy – Use numpy.ndarray in Theano-compiled functions.
2）transparent use of a GPU – Perform data-intensive calculations up to 140x faster than with CPU.(float32 only)
3）efficient symbolic differentiation – Theano does your derivatives for function with one or many inputs.
4）speed and stability optimizations – Get the right answer for log(1+x) even when x is really tiny.
5）dynamic C code generation – Evaluate expressions faster.
6） extensive unit-testing and self-verification – Detect and diagnose many types of mistake.
Theano has been powering large-scale computationally intensive scientific investigations since 2007. But it is also approachable enough to be used in the classroom (IFT6266 at the University of Montreal).

“Theano 是一个 Python 库，用来定义、优化和模拟数学表达式计算，用于高效的解决多维数组的计算问题。Theano的特点：紧密集成Numpy；高效的数据密集型GPU计算；高效的符号微分运算；高速和稳定的优化；动态生成c代码；广泛的单元测试和自我验证。自2007年以来，Theano已被广泛应用于科学运算。theano使得构建深度学习模型更加容易，可以快速实现多种模型。PS：Theano，一位希腊美女，Croton最有权势的Milo的女儿，后来成为了毕达哥拉斯的老婆。”

12. Pylearn2