Python String

Till now, we have discussed numbers as the standard data types in python. In this section of the tutorial, we will discuss the most popular data type in python i.e., string.

In python, strings can be created by enclosing the character or the sequence of characters in the quotes. Python allows us to use single quotes, double quotes, or triple quotes to create the string.

Consider the following example in python to create a string.

str = "Hi Python !"

Here, if we check the type of the variable str using a python script

print(type(str)), then it will print string (str).

In python, strings are treated as the sequence of strings which means that python doesn't support the character data type instead a single character written as 'p' is treated as the string of length 1.

Strings indexing and splitting

Like other languages, the indexing of the python strings starts from 0. For example, The string "HELLO" is indexed as given in the below figure.

As shown in python, the slice operator [] is used to access the individual characters of the string. However, we can use the : (colon) operator in python to access the substring. Consider the following example.

Here, we must notice that the upper range given in the slice operator is always exclusive i.e., if str = 'python' is given, then str[1:3] will always include str[1] = 'p', str[2] = 'y', str[3] = 't' and nothing else.

Reassigning strings

Updating the content of the strings is as easy as assigning it to a new string. The string object doesn't support item assignment i.e., A string can only be replaced with a new string since its content can not be partially replaced. Strings are immutable in python.

Consider the following example.

str = "HELLO"
str[0] = "h"
print(str)

However, in example 1, the string str can be completely assigned to a new content as specified in the following example.

str = "HELLO"
print(str)
str = "hello"
print(str)

String Operators

Consider the following example to understand the real use of Python operators.

str = "Hello" 
str1 = " world"
print(str*3) # prints HelloHelloHello
print(str+str1)# prints Hello world	
print(str[4]) # prints o			
print(str[2:4]); # prints ll				
print('w' in str) # prints false as w is not present in str
print('wo' not in str1) # prints false as wo is present in str1. 
print(r'C://python37') # prints C://python37 as it is written
print("The string str : %s"%(str)) # prints The string str : Hello

Python Formatting operator

Python allows us to use the format specifiers used in C's printf statement. The format specifiers in python are treated in the same way as they are treated in C. However, Python provides an additional operator % which is used as an interface between the format specifiers and their values. In other words, we can say that it binds the format specifiers to the values.

Consider the following example.

Integer = 10;
Float = 1.290
String = "Ayush"
print("Hi I am Integer ... My value is %d\nHi I am float ... My value is %f\nHi I am string ... My value is %s"%(Integer,Float,String));

Built-in String functions

Python provides various in-built functions that are used for string handling. Many String fun