8 Great Python Libraries for Machine Learning

​Python is a great language for developers and scripters alike. It allows for some large scale design and OOP concepts. However, it was also developed to be very easy to read and design quick scripts! This is great, because data scientists don’t have all day to spend debugging. They do need to spend some time picking out which python languages will work best for their current projects. We at Acheron Analytics have written up a quick list of the 8 most used libraries that can help your next machine learning projects.

P.s....we had a busy week and couldn't get to an actual code example this week as we promised in our last post. However, we are working on that post! We will shortly have an example in R for a from scratch algorithm.

Theano

Theano, according to Opensource.com is one of the most heavily used machine learning libraries to date. The great things about Theano, is it is written leaning on mathematical concepts and computer algebra. When the code is compiled it has the ability to to match C level code.
This is due to the fact that it is written to take advantage of how computer compilers work. This in short is how a computer parses and converts tokens into parse trees, how it optimizes and merges similar sub-graphs, using GPU for computations and several other optimizations. For the full list, check out the Theano main page.

For those who used math based languages like Mathamatic and Matlab, the coding structure won’t seem to strange.

​What is great, is that Nvidia fully supports Theano and has a few helpful videos on how to use Theano and their GPUs.

 
​Pandas

When it comes down to it. Machine learning and data science must have good data. How do you handle that data? Well, one great python library is Pandas. It was one of the first data languages many of us were exposed to at Acheron and still has a great following. If you are an R programmer, you will enjoy this language. It allows you to use data frames, which makes thinking about the data you are using much more natural.

Also, if you are a SQL or RDBMS person, this language naturally fits with your tabular view of data. Even if you are more of a Hadoop or MongoDB follower, Pandas just makes life easier.

It doesn’t stop there, it handles missing data, time series, IO and data transformations incredibly well. Thus, if you are trying to prepare your data for analysis, this python language is a must. ​ 

We also wanted to share this great python cheat sheet we found, however, we would feel wrong just stick it on our blog. Instead, here is a link to the best python cheat we have found yet! This even beats Datacamp's cheat sheets!

​NumPy

NumPy is another data managing library. Typically you see it paired with Tensorflow, SciPy, matplotlib and so many other python libraries geared towards deep learning and data science. This is because it is built to manage and treat data like matrices. Again, going back to Matlab and R. The purpose is to provide the ability to do complex matrix operations that are required by neural networks and complex statistics easily.

Trying to handle those kind of operations in multi-dimensional arrays or lists is not the most efficient.


Let's say you want to set up an identity matrix? That is one line of code in numpy. Everything about it is geared towards matrices and quick mathematical operations that are done in just a few lines. Coursea has a great course that you can use to further your knowledge about this library.

​How to code for an Identity Matrix:
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np.identity(3)
array([[ 1.,  0.,  0.],
            [ 0.,  1.,  0.],
           [ 0.,  0.,  1.]])

Scrapy

This is an odd one out. Scrapy is not a mathematical language, it doesn’t perform data analysis, or deep learning. It does nothing you would think you would want to do in machine learning. However, it does one thing really well. That is, crawl the web. Scrapy is built to be an easy language to develop safe web crawlers (side note, make sure you read all the documentation, it is built to be a safe web crawling library if you configure it right and that is something you have to research).

The web is a great source of unstructured, structured, and visual data. As long as a sight approves of you crawling and doesn’t mind you using their content(which we are not responsible for figuring out) you can gain a lot of insight into topics. You can use libraries that take words and put them into vectors to help perform analysis, or sentiment analysis, etc. It is much more difficult than using straightforward numbers. It is also much richer. There is alot to be gained fom pictures, words, and unstructured data. With that comes the task of getting that information how of the complex data.

That being said Pattern is another specialized web mining scraper. It has tools for Natural Language Processing(NLP), and Machine Learning. It has several built in algorithms and really makes your life as developer much easier!


scikit-learn
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We have discussed several libraries such as matplotlib, numPy and Pandas and how great they are for machine learning and data science. Now, imagine if you built and easy to use library on top of all of those, as well as several other easy to use libraries. Well, that is what scikit-learn is. It is a compilation of these libraries to create easy access to complex data science algorithms, data visualization techniques.It can be used for clustering, transforming data, dimensional reduction (reducing the number of features that exist), ensemble methods, feature selection and a lot of other classic data science techniques and they are all basically done in a few lines!

The hardest part is making sure you have a virtual python library when you pip install!

matplotlib and ggplot 

Now you have done all this analysis, and run all your algorithms. What now? How do you actually turn around value from all this data you have. How do you inspire your executives and tell them “Stories” full of “Insight” etc. If you don’t want to mess around with D3.js, python has you covered! Using Libraries like matplotlib and ggplot. Both are really built to mimic matlab and R functionality. Matplotlib has some great 3D graphs that will help you visualize your knn and PCA algorithms and clusters. 

When you are in your data exploration phase, hypothesis, and final product phase of a product. Using these three languages makes life much easier. You can visualize your data, its quirks and your final results!

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Different Machine Learning Models picture from Analyticbridge.com Click to read more!

Tensorflow..again!

​We have discussed Tensorflow before on this blog when we talked about some common libraries used by data science professionals. It doesn't hurt to talk about it again though! The fact is, if you are in the world of machine learning, you have probably heard, tried, or implemented some form of deep learning algorithm. Are they necessary, not all the time. Are they cool when done right, yes.

Tensorflow and Theano are very similar. The interesting thing about Tensorflow, is that when you are writing in python, you are really only design a graph for the compiler to compile into C++ code and then run on either your CPU or GPU. This is what makes this language so effective and easy to work with. Instead of having to write at the C++ or CUDA level, you can code it all in python first.

The difficulty comes in actually understanding how to properly set up a neural network, convolutional network, etc. A lot of questions come into play, which type of model, what type of data regularization do you think is best, what level of data dropout or robustness do you want and are you going to purchase GPUs from Nvidia or try to make it work on CPUs?(Pending on your data size, you will most likely have to purchase, or pay for AI as a service tech from Google).



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​These are just a few of the most commonly mentioned python libraries that are utilized by academics and professionals. Do you agree? Feel free to share what languages, libraries and tools you use, even if they aren’t python!