Python String operations

In my earlier article, I covered Python numeric and String variables. Python supports several String operations. In this article, I will be demonstrating the Python String operations

Introduction

You can create String variables by simply assigning a String value to the variable name. The String variable can be enclosed either in single quotes or double quotes. The following code demonstrates this:

a = 'Hello'
b = "world"

This code creates two String variables aand b

How Python treats Strings

Python treats Strings as a sequence of character. The first character is at position 0 and the last character is at a position which is equal to the length of the String -1. In addition, the end of the String is considered to be at -1 position.

For example consider the String “Hello World“. In forward direction the character ‘H‘ is at position 0 and the character ‘d‘ is at position 10. In the backward direction, the character ‘d‘ is at position -1 and the character ‘H‘ is at position -11.

Slice Operator

The slice operator helps to create substrings.  It consists of [] or [:].  In order to create sun-strings, you need to specify the position within the slice operator. The following code demonstrates this:

str = 'This is a Java program'

print(str[0])
print(str[0:4])
print(str[10:])
print(str[:4])
print(str[-1])
print(str[5:-1])
print(str[-7:-1])

This code prints the following output:

T
This
Java program
This
m
is a Java progra
progra

Concatenation Operator

Just like in Java, the ‘+‘ operator acts as the concatenation operator. It helps in concatenating Strings. The following code demonstrates this:

str1='Hello'
str2 = ' World'
str3 = str1+str2
print(str3)

This code prints the following output:

Hello World

Repetition Operator

The repetition operator(*) helps to repeat a String. You need to specify the String to be repeated, followed by the repetition operator, followed by the number of times the String should be repeated. The following code demonstrates this:

str1='Hello '
str2 = str1*5
print(str2)

This code repeats the String “Hello ” 5 times. So this code prints the following output:

Hello Hello Hello Hello Hello

Further Learning

The Python Masterclass
Everything you need to know about Python
Python for beginners
Python for finance

Conclusion

So in this article, we took at look at the String operations supported by Python. We understood the slice operator, concatenation operator and the repetition operator.