Scikit learn library in Python

mahesh reddy
5 min readMar 26, 2021

Scikit-learn is a free Python Machine Learning Library. It is a very useful tool for data mining and data processing and can be used for both personal and commercial purposes. Scikit-learn is potentially the most useful library for machine learning in Python. The sklearn library provides a range of powerful methods for machine learning and statistical analysis, including classification, regression, clustering and dimensional reduction.

Python Scikit-learn allows users to perform various Machine Learning tasks and provides a means to incorporate Machine Learning in Python. It needs to work with Python ‘s scientific and numerical libraries, namely Python SciPy and Python NumPy, respectively. It’s basically a SciPy toolkit that features a variety of Machine Learning algorithms.

Scikit-learn has small standard datasets that we do not need to download from any external website. We can import these datasets directly from Python Online Training. Below is a list of the datasets that come with Scikit-learn.

1. Boston House Price Dataset

2. Dataset of Iris Plants

3. Dataset of diabetes

4. Dataset of digits

5. Dataset for Wine Identification

6. Dataset of breast cancer

Here, you are going to use the Iris Plants Dataset throughout this article. The data set consists of four fields, namely sepal length, sepal width, petal length and petal width. It also has a super class that comprises three different species, Iris setosa, Iris versicolor, and Iris virginica. These are basically the types of Iris plants, and the data in our dataset, i.e. the Iris plants, is divided into these three classes.

Let us demonstrate how to import this dataset and then perform Machine Learning algorithms on it. We can import the same or any of these datasets in the same way as we do in this tutorial.

Prerequisites for software:

There are some Python libraries that you have to install before we can start installing Scikit-learn, since Python Scikit-learn builds these tools to support Python ‘s scientific and numerical libraries. The following are the tools and libraries that we need to pre-install before using Scikit-learn:

  • Python (2.7 or higher)
  • NumPy (1.6.1 or higher)
  • SciPy (0.9 or above)
  • Scikit-Learn

Need for Python Scikit-learn

There are not many threads on the Internet where we can actually find the reasons why Scikit-learn has become popular with Data Scientists. But it has some obvious benefits that justify why Scikit-learn is used and admired by organizations. Any of these advantages are set out below.

Benefits of Scikit-Learn

BSD license:

Scikit-learn has a BSD license. Therefore, there are minimal restrictions on the use and distribution of the software, making it free for everyone to use.

Easy to use:

The popularity of Scikit-learn is due to the ease of use it offers.

Document Detailing:

It also provides a document detailing the API that users can access on the website at any time, helping them integrate Machine Learning into their own platforms.

Extensive use in the industry:

Scikit-learn is widely used by various organizations to predict consumer behavior, identify suspicious activities, and much more.

Machine Learning Algorithms:

Scikit-learn covers most of the Machine Learning Algorithms Massive community support: being able to perform Machine Learning tasks using Learn Python has been one of the most important reasons behind Scikit-learn ‘s popularity, as Python is easy to learn and already has a huge user community that can now perform Machine Learning on a platform.

Algorithms flowchart:

Unlike other programming languages where users usually have a problem choosing between multiple competing implementations of the same algorithms, Scikit-learn has an algorithm cheat sheet or flowchart to assist users.

Scikit-learn components:

Scikit-learn comes with a lot of features. Here are a few of them that will help you understand the spread:

Supervised Learning Algorithms:

Think about some supervised machine learning algorithm that you may have learned about, and there’s a very strong probability that it’s part about scikit-learn. Starting from Generalized Linear Models (e.g. Linear Regression), Vector Support Machines (SVM), Decision Trees to Bayesian Methods — all of them are part of the Scikit-Learn Toolbox. The proliferation of machine learning algorithms is one of the main reasons for the high use of scikit-learn. I started using scikit to solve supervised learning problems, and I would suggest it to people who are new to scikit / machine learning as well.

Cross-validation:

Various methods exist to check the accuracy of monitored models of unseen data using sklearn.

Unsupervised learning algorithms:

Again, there is a wide range of machine learning algorithms in the offering — from clustering, factor analysis, main component analysis to unsupervised neural networks.

Various toy datasets:

This was useful when studying skikit-learn. I learned SAS using a variety of academic datasets (e.g. IRIS dataset, Boston House price dataset). Having them handy while learning a new library has helped a lot.

Extraction feature:

Scikit-learn how to extract features from images and text (e.g. word bag)

Now that you understand the environment at a high level, let me give an example of the use of sklearn. The aim is to demonstrate the ease of the use of sklearn. We’re going to take a look at various algorithms and the best way to use them in one of the posts that follow.

You will create a logistic regression on the dataset of IRIS:

Step 1:

Download the respective libraries and read the dataset

Add numpy to np

  • Export of matplotlib as plt
  • Export datasets from sklearn
  • Export metrics from sklearn
  • Import LogisticRegression from sklearn.linear model
  • You have imported both of the collections. First, read the dataset:

Dataset = dataset.load iris)

Step 2:

Consider datasets by looking at distributions and plots.

Step 3:

Construct a logistic regression model on the dataset and make predictions.

Model.fit(dataset.data.data, dataset.target)

Planned = dataset.

Forecast = model.forecast(dataset.data)

Step 4:

Print a matrix of uncertainty

Print(metrics.classification report(expected, forecast))

Print(metrics.confusion matrix(expected, expected))

Visualization of data

Having done a data scan with our dataset, now let’s build some plots to visually reflect the data in our dataset that will help us discover more stories hidden in it.

Python has several libraries that provide data visualization features for datasets. We can use the.plot extension of Pandas to create a scatterplot of features or fields of our dataset against each other, and you also need to import python matplotlib.

Inputs:

Import scatter matrix from pandas.plotting

Export as plt matplotlib.pyplot

Scatter matrix(df iris, figsize=(10,10)))

Plat.show)

Output:

You can also use the Seaborn library to build pair plots of all dataset features against each other. Next, we need to import the Seaborn Library to use Seaborn. Let’s see how this is done and how to create a Seaborn Pair.

Inputs:

Imports seaborn as sns

Sns.set(style=”ticks “and color codes = True)

dfiris = sns.load dataset(‘iris’)

Sns.pairplot(dfiris, hue=’species’)

Scikit ‘s learning Python has proven its value by being able to help professionals face challenges while applying predictive models. Scikit Python is not limited to the IT industry. It has different applications in a variety of sectors. It can be used to apply Machine Learning and can be combined with data visualization, making Machine Learning even more important. With all the benefits it has, it’s easy to say that Scikit Python has a wide range.

Conclusion

I hope you reach to a conclusion about the Scikit learn library in python. You can learn more through Python online training.

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mahesh reddy

Python certification training course will help you master the concepts and gain in-depth experience on writing Python code and packages like SciPy, Matplotlib,