What is the difference between "lambda" and "def" in Python?
Table of Contents
Introduction
In Python, both lambda
and def
are used to define functions, but they serve different purposes and have distinct syntax and use cases. Understanding the differences between lambda
and def
is essential for writing clear and effective code. This article explores these differences, including syntax, functionality, and practical applications.
Key Differences Between lambda
and def
1. Syntax and Definition
lambda
: Thelambda
keyword is used to create small, anonymous functions, often referred to as lambda functions. These functions are defined in a single line of code and are typically used for short-term operations or as arguments to higher-order functions.def
: Thedef
keyword is used to create named functions with more extensive functionality. Functions defined withdef
can contain multiple lines of code, have a name, and can include complex logic, documentation, and default values.
Example:
2. Functionality and Use Cases
lambda
: Lambda functions are generally used for short, throwaway functions that are not needed beyond a single expression. They are often used with functions likemap()
,filter()
, andsorted()
where a small function is needed temporarily.def
: Functions defined withdef
are more versatile and can be used for more complex operations. They are suitable for cases where functions need to be reused, involve multiple statements, or require extensive documentation.
Example:
3. Limitations
lambda
: Lambda functions are limited to a single expression. They cannot contain multiple expressions, statements, or annotations. They also lack a name and documentation, which can make debugging and readability more challenging.def
: Functions defined withdef
can include multiple statements, complex logic, and support for documentation strings (docstrings). They also allow for better readability, debugging, and reuse.
Example:
Practical Examples
Example : Lambda for Inline Operations
Example : Def for Reusable Functions
Conclusion
In Python, lambda
and def
serve different purposes for function definition. lambda
is used for creating short, anonymous functions suitable for quick, temporary use, while def
is used for defining named functions with more extensive functionality, multiple statements, and better documentation. Choosing between lambda
and def
depends on the complexity of the function and its intended use.