How Do Positional and Keyword Arguments Differ in Python Functions?

Understanding Keyword Arguments in Python

In Python, function arguments can be passed in two different ways: normal (positional) arguments and keyword arguments. Normal arguments are passed in the order they are defined in the function, while keyword arguments are passed by name.

Difference Between Normal and Keyword Arguments

The key distinction between normal and keyword arguments lies in their specification:

• Normal arguments: Passed in the order of definition without explicitly specifying names.
• Keyword arguments: Passed using the syntax name=value after all normal arguments.

Positional Arguments

Positional arguments adhere to the order defined in the function signature. For example:

def my_function(a, b, c):
    pass

When calling my_function, the arguments must be passed in the correct order:

my_function(1, 2, 3)

Keyword Arguments

Keyword arguments allow you to specify argument names explicitly. This provides flexibility in the order of argument passing and enables the use of default values for optional arguments.

# Defining a function with default values
def my_function(a, b, c=4):
    pass

# Passing keyword arguments out of order
my_function(a=1, c=5, b=2)

Pure Keyword Arguments

In certain situations, you may want to define functions that accept keyword arguments only. This is known as pure keyword arguments. The syntax is:

def my_function(**kwargs):
    pass

Any keyword arguments passed to my_function will be stored in a dictionary named kwargs, which can be accessed at runtime.

my_function(a=1, b="abc")
print(kwargs)
# {'a': 1, 'b': 'abc'}

Conclusion

Keyword arguments offer powerful means to enhance flexibility and readability in Python functions. They support out-of-order argument passing, optional arguments, and pure keyword argument definition. By leveraging keyword arguments effectively, developers can create robust and user-friendly code.

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