Functions

6.1 Introduction to Functions

• 6.1.1 Meaning of Function
• 6.1.2 Need for Functions
• 6.1.3 Advantages of Functions
• 6.1.4 Types of Functions in Python
• 6.1.5 Built-in Functions
• 6.1.6 User-Defined Functions

6.2 Top-Down Approach of Problem Solving

• 6.2.1 Meaning of Top-Down Approach
• 6.2.2 Steps of Top-Down Problem Solving
• 6.2.3 Problem Decomposition
• 6.2.4 Example of Top-Down Approach

6.3 Modular Programming and Functions

• 6.3.1 Meaning of Modular Programming
• 6.3.2 Need for Modular Programming
• 6.3.3 Advantages of Modular Programming
• 6.3.4 Functions as Modules
• 6.3.5 Example of Modular Programming

6.4 Defining and Calling Functions

• 6.4.1 Function Definition
• 6.4.2 Function Calling
• 6.4.3 Syntax of Function
• 6.4.4 Function with No Parameters
• 6.4.5 Function with Parameters
• 6.4.6 Function with Return Value

6.5 Function Parameters

• 6.5.1 Meaning of Parameters
• 6.5.2 Actual and Formal Parameters
• 6.5.3 Positional Arguments
• 6.5.4 Parameter Passing
• 6.5.5 Multiple Parameters

6.6 Local Variables

• 6.6.1 Meaning of Local Variable
• 6.6.2 Scope of Local Variable
• 6.6.3 Local Variable Example
• 6.6.4 Local vs Global Variables

6.7 The return Statement

• 6.7.1 Introduction to return
• 6.7.2 Returning a Single Value
• 6.7.3 Returning Multiple Values
• 6.7.4 Function Without return
• 6.7.5 Difference Between print() and return

6.8 DocStrings

• 6.8.1 Meaning of DocString
• 6.8.2 Writing a DocString
• 6.8.3 Accessing DocString
• 6.8.4 Importance of DocStrings

6.9 Global Statement

• 6.9.1 Global Variables
• 6.9.2 global Statement
• 6.9.3 Modifying Global Variables
• 6.9.4 Local and Global Variable Example

6.10 Default Argument Values

• 6.10.1 Meaning of Default Arguments
• 6.10.2 Defining Default Arguments
• 6.10.3 Calling Function with Default Arguments
• 6.10.4 Multiple Default Arguments

6.11 Keyword Arguments

• 6.11.1 Meaning of Keyword Arguments
• 6.11.2 Using Keyword Arguments
• 6.11.3 Positional vs Keyword Arguments
• 6.11.4 Advantages of Keyword Arguments

6.12 VarArgs Parameters

• 6.12.1 Variable-Length Arguments
• 6.12.2 *args
• 6.12.3 **kwargs
• 6.12.4 Difference Between *args and **kwargs
• 6.12.5 Examples of VarArgs Functions

6.13 Library / Built-in Functions 6.13.1 Input and Output Functions

• input()
• eval()
• print()

6.13.2 String Functions

• count()
• find()
• rfind()
• capitalize()
• title()
• lower()
• upper()
• swapcase()
• islower()
• isupper()
• istitle()
• replace()
• strip()
• lstrip()
• rstrip()
• split()
• partition()
• join()
• isspace()
• isalpha()
• isdigit()
• isalnum()
• startswith()
• endswith()
• encode()
• decode()

6.13.3 String Slicing

• 6.13.3.1 String Indexing
• 6.13.3.2 String Slicing
• 6.13.3.3 Negative Indexing
• 6.13.3.4 Slicing with Step
• 6.13.3.5 Reverse String Using Slicing

6.13.4 String Membership

• in Operator
• not in Operator
• Searching Substrings

6.13.5 Pattern Matching

• 6.13.5.1 Introduction to Pattern Matching
• 6.13.5.2 Basic Pattern Searching
• 6.13.5.3 String Pattern Examples

6.14 Numeric Functions

• 6.14.1 eval()
• 6.14.2 max()
• 6.14.3 min()
• 6.14.4 pow()
• 6.14.5 round()
• 6.14.6 int()
• 6.14.7 random()
• 6.14.8 ceil()
• 6.14.9 floor()
• 6.14.10 sqrt()