How Does Python Handle Variable Arguments in Functions?

Passing Variable Arguments to Functions

In programming, there are often scenarios where a function needs to accept a variable number of arguments. In C and C , this is achieved using varargs.

Python's Approach

Python also supports this feature, but it takes a slightly different approach:

Non-Keyword Arguments:

To accept a variable number of non-keyword arguments, you can use the special syntax *args. When a function is called with more arguments than the defined parameters, the extra arguments are automatically collected into a tuple named args.

def manyArgs(*args):
  print("I was called with", len(args), "arguments:", args)

manyArgs(1)  # Output: I was called with 1 arguments: (1,)
manyArgs(1, 2, 3)  # Output: I was called with 3 arguments: (1, 2, 3)

Python automatically unpacks the arguments into a tuple, making it easy to access each argument individually.

Keyword Arguments:

Unlike varargs in C/C , Python does not allow variable keyword arguments in the same way. To support variable keyword arguments, you need to manually specify a separate parameter for keyword arguments, typically named **kwargs.

def manyArgsWithKwargs(num, *args, **kwargs):
  # Non-keyword arguments
  print(f"Non-keyword arguments: {args}")

  # Keyword arguments
  print(f"Keyword arguments: {kwargs}")

manyArgsWithKwargs(1, 2, 3, key1="value1", key2="value2")

This approach allows you to accept a variable number of both non-keyword and keyword arguments in the same function.

The above is the detailed content of How Does Python Handle Variable Arguments in Functions?. For more information, please follow other related articles on the PHP Chinese website!