Putting *args and/or **kwargs as the last items in your function definition’s argument list allows that function to accept an arbitrary number of arguments and/or keyword arguments.

2008年8月31日 · *args (typically said "star-args") and **kwargs (stars can be implied by saying "kwargs", but be explicit with "double-star kwargs") are common idioms of Python for using the * and ** notation. These specific variable names aren't required (e.g. you could use *foos and **bars ), but a departure from convention is likely to enrage your fellow ...

*args and **kwargs are special-magic features of Python. Think of a function that could have an unknown number of arguments. For example, for whatever reasons, you want to have function that sums an unknown number of numbers (and you don't want to use the built-in sum function).

2014年5月19日 · args = (1, 2) kwargs = {'last': 'Doe', 'first': 'John'} self.save_name_for(*args, **kwargs) the * and ** act as unpacking operators. args must be an iterable, and kwargs must be dict-like. The items in args will be unpacked and sent to the function as positional arguments, and the key/value pairs in kwargs will be sent to the function as ...

I highly recommend argparse which comes with Python 2.7 and later.. The argparse module reduces boiler plate code and makes your code more robust, because the module handles all standard use cases (including subcommands), generates the help and usage for you, checks and sanitize the user input - all stuff you have to worry about when you are using sys.argv approach.

In Python 2.x (I use 2.7), which is the proper way to use default arguments with *args and **kwargs? I've found a question on SO related to this topic, but that is for Python 3: Calling a Python function with *args,**kwargs and optional / default arguments. There, they …

2009年5月28日 · Yes. You can use *args as a non-keyword argument. You will then be able to pass any number of arguments. def manyArgs(*arg): print "I was called with", len(arg), "arguments:", arg >>> manyArgs(1) I was called with 1 arguments: (1,) >>> manyArgs(1, 2, 3) I was called with 3 arguments: (1, 2, 3)

2015年5月27日 · I would like to check whether an optional argparse argument has been set by the user or not. Can I safely check using isset?

A Python function can take in some arguments, take this for example, def add(x,y): return x+ y # calling this will require only x and y add(2,3) # 5 If we want to add as many arguments as we may want, we shall just use *args which shall be a list of more arguments than the number of formal arguments that you previously defined (x and y).

I've taken the parse_known_intermixed_args function, simplified it for presentation sake, and then made it the parse_known_args function of a Parser subclass. I had to take an extra step to avoid recursion. Finally I changed the _parser_class of the subparsers Action, so each subparser uses this alternative parse_known_args.