Python Strings & Built-in String Methods.pptx

This presentation describes about the strings in python language. It also describes about the built-in string methods available in python.

1. Python Strings Mrs.S.RAJAPRIYA , M.S(IT)., Assistant Professor, Department of Computer Science (self) V.V.Vanniaperumal College for Women, Virudhunagar

2. Python Strings Python treats strings as contiguous series of characters delimited by single, double or even triple quotes . We can declare and define a string by creating a variable of string type. This can be done in several ways which are as follows: name = "India" graduate = 'N‘ country = name nationality = str ("Indian") Built-in String Class

3. Three Main Operations in string Concatenating: We can concatenate two strings using + operator. Example: s1=“Welcome to “ s2=“Python Programming” s3=s1+s2 print(s3) Output: Welcome to Python Programming

4. Three Main Operations in string Appending: We can add one string to the end of another string using append operator +=. Example: s1=“Hello,“ name=input(“Enter Your Name:”) s1 += name s1 += “.Welcome to the World of Python” print(s1) Output: Enter Your Name: Arun Hello, Arun .Welcome to the World of Python

5. Three Main Operations in string Repeating: We can repeat a given string n number of times using * operator . Example: s1=“Hello World“ print(s1*3) Output: Hello World Hello World Hello World

6. Str () function The str () function is used to convert values of any data type to string type. Example: s1=“Hello” s1=“Hello” n=7 n=7 s2=s1+str(n) s2=s1+n print(s2) print(s2) Output : Hello7 Output: TypeError

7. Strings are Immutable Python strings are immutable which means that once created they cannot be changed . Whenever you try to modify an existing string variable, a new string is created. Using id() function, we can identify the memory address of a particular object. Example: Program to demonstrate string references using id() function s1 = “Hello” Output print(s1) Hello print(id(s1)) 45093344 s2 = “World” World print(s2) 45093312 print(id(s2)) s1 += s2 print(s1) Hello World print(id(s1)) 43861792

8. Built-in String Methods Python support various built-in methods to manipulate strings. Each method is invoked or calle d on an object. Some of the commonly used built-in methods are:

9. Built-in String Methods

10. Built-in String Methods

11. Thank You