Learning Python Smart Way : Numbers & Strings

In this series of blogs we will learn python , But in a smart way, I mean by smart way  learning  python learning deep with basics and learn only needful things that we are going to implement in future project and in more practical manner.

Here I discussed about Installing Python and Starting IDLE . Lets start with Numbers and Strings.

Numbers  :-

We will learn about following topics :-

1. Type of Number in Python.
2. Arithmetic operations.
3. Assignment of Object

Type of Number in Python :-

In python , We have lots of type of numbers,  I will mainly discuss about Integers and Floating point numbers.
Integer example is  1. –2 etc and Floating point number is 3.01 etc.

Basic Operations example :

Arithmetic operations:-

Note : In python 2, If you divide 3/2 you will get the integer by in python 3 you will get the float value.

In you have python 2 installed , You can import division module from  “__future__” to get the Floating point number.

Assignment of Object:-

In python , Lets create some variables, In python we can assign any data type  to a variables that why I love python most.
Using print(“ ”) function to print values e.g variables in the below image.

The names you use when creating these labels need to follow a few rules:

  1. Names can not start with a number.
  2. There can be no spaces in the name, use _ instead.
  3. Can’t use any of these symbols :'”,<>/?|\()!@#$%^&*~-+.
  4. It’s considered best practice (PEP8) that the names are lowercase.

Strings :-

Lets learn following topics in strings.

  1. Creating & Printing Strings
  2. String Indexing and Slicing
  3. String Properties &  Methods
  4. Formatting Print
Creating & Printing Strings

String Indexing and Slicing

We can use a : to perform slicing which grabs everything up to a designated point.

Note :  The slicing Here we’re telling Python to grab everything from 1 up to 2. It doesn’t include the 2rd index. You’ll notice this a lot in Python, where statements and are usually in the context of “up to, but not including”.

We can also use index and slice notation to grab elements of a sequence by a specified step size (the default is 1). For instance we can use two colons in a row and then a number specifying the frequency to grab elements. For example:

# Grab everything, but go in steps size of 1.
# Grab everything, but go in steps size of 2
# We can use this to print a string backwards by (-1)

String Properties &  Methods

Its important to note that strings have an important property known as immutability.

s = ‘Hello World’
# Let’s try to change the first letter to ‘x’
s[0] = ‘x’

Formatting Print

That’s all folks , In next series we will learn about List, Dictionaries and Tuples.