Named argument

As explained in Python How-To

A keyword argument is a function argument supplied by associating an explicit parameter name with its value.

A named argument, also called a keyword argument, supplies a value by naming the corresponding parameter. Unlike positional arguments, keyword arguments do not depend on their order. section 6.4.1

Call a function with named arguments

For a function such as `def multiply_numbers(a, b): return a * b`, these calls produce the same result: `multiply_numbers(2, 3)` and `multiply_numbers(a=2, b=3)`. Reordering the names remains valid: `multiply_numbers(b=3, a=2)`. When combining styles, place positional arguments first: `multiply_numbers(2, b=3)`. section 6.4.1

Use named arguments to make function calls clearer and to handle flexible interfaces:

• Match values to parameters by identifier rather than by position. section 6.4.1
• Keep positional arguments before named arguments; otherwise Python raises a `SyntaxError`. section 6.4.1
• Accept an arbitrary number of named arguments with `**kwargs`; Python collects them into a dictionary. section 6.4.3
• Use valid identifiers for keyword names; names cannot begin with a number. section 6.4.5

Figure 6.6 Using positional and keyword arguments in function calls. If the arguments have identifiers preceding the arguments, they’re keyword arguments. If the arguments have no identifiers, they’re positional arguments.

Compare positional and named arguments visually through representative function calls. section 6.4.1

How Python How-To covers it

How deep it goes

Explains identifier-based matching, ordering rules, flexible **kwargs, and invalid names without descending into interpreter internals.

Examples

Demonstrates multiply_numbers calls, print's named options, create_report with grades, and valid or invalid **kwargs calls.

What it assumes

Assumes basic familiarity with Python functions, parameters, and calls while distinguishing positional and named argument behavior explicitly.

What you can do after

Apply named arguments in function calls, combine them correctly with positional arguments, and define flexible interfaces with **kwargs.

How it connects

Connects named arguments with positional arguments, **kwargs, default arguments, type hints, and docstrings.

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Also explained in

• 

  liveBookmanning.com
  Python Workout, Second EditionA keyword argument is an argument passed by associating a value with a parameter name in a function call.
• 

  liveBookmanning.com
  Kotlin in Action, 2ENamed-argument syntax specifies function or constructor arguments by writing each argument's parameter name explicitly.

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Related concepts

• positional argumentcontrasts with · A positional argument is a function argument associated with a parameter according to its ordinal position in the call rather than its name.
• **kwargsused by · **kwargs is Python function-parameter syntax that collects arbitrary keyword arguments into a dictionary keyed by their names.
• functionuses · A function is a defined operation that maps inputs to outputs and, when implemented as a callable program unit, may also produce effects.
• required argumentincludes · A required argument is an input value that must be supplied for a function, command, operation, or request to be valid.
• format methodused by · A format method is an API operation that produces a formatted representation by substituting supplied values into a formatting specification.
• parameter bindingcontrasts with · Parameter binding is PowerShell's process of mapping supplied arguments or pipeline objects to a command's parameters.

This explainer was generated by Manning's knowledge graph from the text of Python How-To. The section links point to the parts of the book it draws on.