Variables and Data Types in Python. Part 2 Python Course from Beginner to Advanced in 11 blog posts

This article will help the reader understand about the basic data types in Python, variables, some commonly used functions with respect to data types and some basic applications in real world. We will be using Visual Studio Code as our code editor. If you have not installed Visual Studio Code, the instructions is given in the previous blog post.

Variables and Data Types in Python – table of contents:

1. Introduction to Python
2. Variables in Python
3. Data types in Python
4. Next Blog Glimpse

Introduction to Python

As we have learned in the previous blog post that Python is a high-level, interpreted, dynamically typed, and object-oriented language. Due to its high-level nature, the language is very easy to learn, and syntax is also simple. There are a variety of applications of python in real-world like for machine learning, data science, game development, web applications, and many more.

In the previous blog post, we learned on how to print text in Python. We used to print (“your desired text”) as the syntax. Let’s start with what are variables and why do we use variables.

Variables in Python

A variable is an entity that stores a value. The value may be a number, integer, real number, text, or a character. Let’s see some examples of how you can use a variable to store values in Python.

# variables
x = 1  # storing integer
y = 2.5  # storing real number
z = "string"  # storing string or text
n = "a"  # storing a character
b = True  # storing a boolean value
print(x,y,z,n,b)

Output:
1 2.5 string a True

We have seen how to store variables, now let’s see how to print their values. You already know the answer, which is to use print(), which we used in the first blog to print the desired text. Also, see that we are using the variables without using any double quotes or single quotes as opposed to before. This is because a variable is recognized by print directly as it is stored in the memory when it is declared. Now, let’s print the variables.

We can see that the variables are printed as highlighted in the above image. As we can see Python supports most of the different data types in Python like integer, float (real numbers), string (text or characters) and Boolean (True or False).

Data types in Python

Strings

What operations can be performed using strings?

• title()

  This function can be used to capitalize the starting letter of each word in the string as seen below the output is highlighted.

text="this blog is awesome"
print(text.title())

This Blog Is Awesome

text="this blog is awesome"
print(text.upper())

output:
THIS BLOG IS AWESOME

text = "this blog is awesome"
print(text.lower())

Output:

this blog is awesome

text = "this blog is awesome"
text2="for beginners"
print(text+text2)

Output:

this blog is awesomefor beginners

print("this blog is \nawesome")
print("\tthis blog is awesome")

Output:

this blog is 
awesome
  this blog is awesome

z=" hello "
print(z)
print(z.strip())
print(z.rstrip())
print(z.lstrip())
Output:
“ hello “
“hello”
“ hello”
“hello “

Z="awesome"
Print(len(Z))

Output:
5

a=1

type(a)

output:

int

Floats

In integer data type variables only, whole numbers can be stored but to include real numbers or to store real numbers we use float. In essence float is used for decimals.

a=1.6

type(a)

output:

float

Operations on Floats and Integers

In our basic mathematics during our high school, we have learned several operations which can be performed on numbers like Addition, Subtraction, Multiplication, Division and many more. We can perform all those operations on floats and integers as illustrated below with code.

# variables

x = 1  # storing integer
y = 2.5  # storing real number
z = "string"  # storing string or text
n = "a"  # storing a character
x = True  # sprint(x,y,z,n,b)toring a boolean value

output:

<class 'bool'> <class 'float'> <class 'str'> <class 'str'> <class 'bool'>

Boolean

In Python there are times where a developer needs to know if a statement is true or false. Mostly when using conditions, the Boolean are used. Boolean consists of True and False. Not that Python is case sensitive when using Booleans, hence they need to be in the True and False format only.

As we have learned about data types in Python and variables in Python, let’s code a simple program and test our knowledge.

• Type Conversion

  The type conversion is a process where you convert one datatype variable into another datatype variable.

• int()

  This converts a number that is in string form or a float to integer value. The example is illustrated below with the code.

a="6"
b=6.5
print(int(a),int(b))

output:

6 6

a="a"

print(int(a))

output:

--------------------------------------------------------------------------- ValueError Traceback (most recent call last) <ipython-input-128-d5a3b8380653> in <module> 1 a="a" 2 ----> 3 print(int(a)) ValueError: invalid literal for int() with base 10: 'a'

a="6.5"
b=7
print(float(a),float(b))

output:

6.5 7.0

a="a"

print(float(a))

output:

--------------------------------------------------------------------------- ValueError Traceback (most recent call last) <ipython-input-130-f48cb0b32023> in <module> 1 a="a" 2 ----> 3 print(float(a)) ValueError: could not convert string to float: 'a'

a = 6
b = 6.7
c = True

print(str(a), str(b), str(c))

output:

6 6.7 True

a = 0
b = 0
c = ""

print(bool(a), bool(b), bool(c))

Next Blog Glimpse

In the next blog post we will be learning about Lists, Tuples, Sets and Dictionaries.

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