Creating charts with python...

Data analysis is of no use until we present it in understandable manner.
And charts are most efficient and conventional way of showing meaning of data.

Here we're going to use the Python library matplotlib to create some graphical charts based on our data.

Sample graph of Time vs Speed

Lets take one simple example to understand how graphs are plotted using matplotlib.

I have two list of values,

   1.Time in hours – 1,2,3,4,5

   2. Speed in mph - 23, 30, 35, 45, 32

Now we will plot a simple chart having Time on  X axis and Speed on Y axis.

Code

Output

Here is your neat and clean time vs speed chart.
If you look at the code, we are importing pyplot module from matplotlib package.
plt.plot() commands take x and y axis values as input and plot the graph.
We can further name axis using xlabel() and ylabel() function.

One more sample problem:

Please refer problem section of my earlier Text analysis with python blog.
There you would see two parameters,
     - Variety of radish
     - Number of votes for each variety of radish
Now we will try to plot a bar graph of the same where x='Variety of radish'
y='Number of Votes'

See below code snippet
Please note that before running below code, I have already created one dictionary object 'count' containing variety of radish as key and number of votes as value.Refer Text analysis with python blog(code 4)

Code

And here is your bar plot,

Try your hands on this Problem.

Happy learning !!!

Text analysis with Python..

What is Python ?

Python is an object-oriented, high level language, interpreted, dynamic and multipurpose programming language.

Python is easy to learn yet powerful and versatile scripting language.

Python for Data Science..

Python is an interpreted, dynamically-typed language with a precise and efficient syntax.

It is open source.

Large active community – You can easily find experts to answer on challenges you face

Growing Data Analytics Libraries like NumPy, SciPy, StatsModels, Scikit-Learn, Pandas, etc.

Let’s get started…

Objective of this blog is to get you started with data processing using python. We will learn fundamentals of working with text, some basic data structures in Python, reading data from text file and processing it to get some insights .

Python Programming Tutorial

Data structures in Python…

List and Dictionaries are two important data structures in Python.

List –

Used to store variables of same/different data type. It is a container that holds other objects in a given order. Different operation like insertion and deletion can be performed on lists.

Creating and printing a simple list

Code

Output

Output

Dictionary –

Dictionary stores data in key-value pair.

The pair i.e., key and value is known as item.

Creating and printing a dictionary

Output

Reading from a text file…

Following code snippet will give you idea on how to read from a text file.

We can further store this extracted in Python data structures to process it further.

Above information is just to get you an overview of python components, specially the one which we are going to use further in this blog. However, no doubt one would need more practice on the same topics..

Problem solving..

Let`s solve some problem with some of skills we tried to acquire and get started with data analysis.

The Problem :

Suppose you're a greengrocer, and you run a survey to see what radish varieties your customers prefer the most. You have your assistant type up the survey results into a text file on your computer, so you have 300 lines of survey data in the file Data File. Each line consists of a name, a hyphen, then a radish variety.

Now we will find out –

1.Which is the most popular radish variety ? (one who has got most votes)

2.Which is least popular radish variety ?

3.We can also find out fraud (People who voted more than once)

Click to refer Detailed problem statement

Now, we will move further with motive of printing which radish has got how many number of votes. This will give us insight on data.

Refer below code snippet 

Output

And, You can see which variety got how many votes.

Our Winner is : 'Champion' with highest 76 votes

And poor least popular radish : 'Red King'

Now, Who voted more than once ?

refer following code snippet..

And Here is your answer,