Python Strings: Exploring string manipulation methods

Strings in python:

String is a sequence of characters which is encapsulated inside single quotes or double quotes.

For example:

“Hello World”
‘Apple’
"What's that?"

These are what strings look like in python.

Types of strings-

1.Single line string- To write a single lined string we use either single quotes('This is a string') or double quotes("This is also a string").

Example- print('Hello world!)
         print("What's up?")
output- Hello world!
        What's up?

1. Multi line string- To write a multi lined string we use single triple quotes(''' ''') or double triple quotes(""" """).

Example- 
print("""We have a pet.
He is a dog.""")

output- We have a pet.
        He is a dog.

String Indexing-

Since a string is an ordered sequence, we can perform indexing on it.

Indexing allows us to grab a single character of the string and access it.

Every single character in a string has an indexed position(index) starting from 0 and ending at n-1(where n= number of characters).

H E L L O
0 1 2 3 4

Example-
my_string= “Hello”
print(my_string[3])

output - l

We can also use reverse indexing in python.

H E L L O
0 -4 -3 -2 -1

Example- 

My_string = “Hello”
print(my_string[-4])

Output - e

SLICING

Slicing allows us to grab a subsection of the string(multiple characters) aka a slice of string.

Syntax of slicing- [start:stop:step]
Where start is the numerical index value from where we have to grab the characters.
Stop is the numerical value we will jump to but not include and
Step is the size of the jump we take from start to stop.

Note- To grab all elements of string we use ::

Example-

My_string = “Hello”
print(my_string[2:4])

output- llo

String slicing will always include the starting letter to the letter before the mentioned index (n-1).

STRING PROPERTIES AND METHODS-

IMMUTABILITY- Strings are immutable which means they cannot be changed.

Example- 
name = “Sam”
name[0] = ‘P’

The above code will give an error because we can’t change strings.

CONCATENATION- We can concatenate(merge) two strings using concatenation.

Example- 
x = “Hello”
x  + “ World!”
Output- Hello World!

You can use * to multiply the number of letters.

Example- 
letter = ‘x’
letter * 10
Output- zzzzzzzzzz

Conclusion-

A string is a sequence of characters which is immutable and you can perform indexing and slicing on it because it is an ordered sequence.