kwargs is a dictionary. Dictionaries are unordered – simply put, the order is unspecified and an implementation detail. Peeking under the hood will show that the order varies wildly depending on the hash values of the items, the order of insertion, etc. so you better don’t rely on anything related to it.
To keep arguments ordered, I use a custom action like this: import argparse class CustomAction(argparse.Action): def __call__(self, parser, namespace, values, option_string=None): if not ‘ordered_args’ in namespace: setattr(namespace, ‘ordered_args’, []) previous = namespace.ordered_args previous.append((self.dest, values)) setattr(namespace, ‘ordered_args’, previous) parser = argparse.ArgumentParser() parser.add_argument(‘–test1’, action=CustomAction) parser.add_argument(‘–test2’, action=CustomAction) To use it, for example: >>> parser.parse_args([‘–test2’, ‘2’, ‘–test1’, ‘1’]) Namespace(ordered_args=[(‘test2’, … Read more
You may want to accept nearly-arbitrary named arguments for a series of reasons — and that’s what the **kw form lets you do. The most common reason is to pass the arguments right on to some other function you’re wrapping (decorators are one case of this, but FAR from the only one!) — in this … Read more
Yes. You do it like this: def method(**kwargs): print kwargs keywords = {‘keyword1’: ‘foo’, ‘keyword2’: ‘bar’} method(keyword1=’foo’, keyword2=’bar’) method(**keywords) Running this in Python confirms these produce identical results: {‘keyword2’: ‘bar’, ‘keyword1’: ‘foo’} {‘keyword2’: ‘bar’, ‘keyword1’: ‘foo’}
You can do that in Python 3. def func(a,b,*args,kw1=None,**kwargs): The bare * is only used when you want to specify keyword only arguments without accepting a variable number of positional arguments with *args. You don’t use two *s. To quote from the grammar, in Python 2, you have parameter_list ::= (defparameter “,”)* ( “*” identifier … Read more
Use keyword argument unpacking: >>> kw = {‘a’: True} >>> f(**kw) <<< ‘a was True’
You can set the fontsize directly in the call to set_xticklabels and set_yticklabels (as noted in previous answers). This will only affect one Axes at a time. ax.set_xticklabels(x_ticks, rotation=0, fontsize=8) ax.set_yticklabels(y_ticks, rotation=0, fontsize=8) Note this method should only be used if you are fixing the positions of the ticks first (e.g. using ax.set_xticks). If you … Read more
Use the double-star (aka double-splat?) operator: func(**{‘type’:’Event’}) is equivalent to func(type=”Event”)
You can pass a default value to get() for keys that are not in the dictionary: self.val2 = kwargs.get(‘val2’,”default value”) However, if you plan on using a particular argument with a particular default value, why not use named arguments in the first place? def __init__(self, val2=”default value”, **kwargs):
You can use **kwargs to let your functions take an arbitrary number of keyword arguments (“kwargs” means “keyword arguments”): >>> def print_keyword_args(**kwargs): … # kwargs is a dict of the keyword args passed to the function … for key, value in kwargs.iteritems(): … print “%s = %s” % (key, value) … >>> print_keyword_args(first_name=”John”, last_name=”Doe”) first_name … Read more