- 5.1 Function Definitions
- 5.2 Default Arguments
- 5.3 Variadic Arguments
- 5.4 Keyword Arguments
- 5.5 Variadic Keyword Arguments
- 5.6 Functions Accepting All Inputs
- 5.7 Positional-Only Arguments
- 5.8 Names, Documentation Strings, and Type Hints
- 5.9 Function Application and Parameter Passing
- 5.10 Return Values
- 5.11 Error Handling
- 5.12 Scoping Rules
- 5.13 Recursion
- 5.14 The lambda Expression
- 5.15 Higher-Order Functions
- 5.16 Argument Passing in Callback Functions
- 5.17 Returning Results from Callbacks
- 5.18 Decorators
- 5.19 Map, Filter, and Reduce
- 5.20 Function Introspection, Attributes, and Signatures
- 5.21 Environment Inspection
- 5.22 Dynamic Code Execution and Creation
- 5.23 Asynchronous Functions and await
- 5.24 Final Words: Thoughts on Functions and Composition
This chapter is from the book
This chapter is from the book
This chapter is from the book
5.24 Final Words: Thoughts on Functions and Composition
Any system is built as a composition of components. In Python, these components include various sorts of libraries and objects. However, underlying everything are functions. Functions are the glue by which a system is put together and the basic mechanism of moving data around.
Much of the discussion in this chapter focused on the nature of functions and their interfaces. How are the inputs presented to a function? How are the outputs handled? How are errors reported? How can all of these things be more tightly controlled and better understood?
The interaction of functions as a potential source of complexity is worth thinking about when working on larger projects. It can often mean the difference between an intuitive easy-to-use API and a mess.