When looking at some built-in functions within builtins.py, I came across the strange syntax<\/p>\n
\r\ndef ascii(*args, **kwargs): \r\n<\/pre>\nThe *args<\/em> and **kwargs<\/em> has a special meaning within Python. The *args<\/em> will give all function parameters as a tuple and the **kwargs<\/em> will give a dictionary of key\/values.<\/p>\n
Note: convention seems to suggest the parameter names args and kwargs, but these are not enforced naming conventions.<\/em><\/p>\n
Let’s see these two (separately) in action<\/p>\n
\r\ndef show_args(*args):\r\n for a in args:\r\n print(a)\r\n\r\n\r\ndef show_key_values(**kwargs):\r\n for a in kwargs:\r\n print(a, kwargs[a])\r\n\r\n\r\nshow_args("Hello", "World", 123)\r\nshow_key_values(first="Hello", second="World", third=123)\r\n<\/pre>\nAs you can see, in the show_args<\/em> function we will list each argument out, hence the output to stdout will be<\/p>\n
\r\nHello\r\nWorld\r\n123\r\n<\/pre>\nThe show_key_values<\/em> expects key\/value input, hence the field\/property name followed by = and then the value. This will output<\/p>\n
\r\nfirst Hello\r\nsecond World\r\nthird 123\r\n<\/pre>\nIn both cases we can also pass no arguments to these methods and nothing will be output, but it’s also not unusual (as can be seen by the ascii<\/em> function at the start of this post) for the two pieces of syntax to be combined, i.e.<\/p>\n
\r\ndef show_args_key_values(*args, **kwargs):\r\n for a in args:\r\n print(a)\r\n\r\n for a in kwargs:\r\n print(a, kwargs[a])\r\n<\/pre>\nand now this can be called in the following ways<\/p>\n
\r\nshow_args_key_values("Hello", "World", 123, first="Hello Again")\r\n<\/pre>\nAs you can probably tell from this syntax, you will need to list the list of arguments before the key\/value list of arguments, but you can write the following<\/p>\n
\r\nshow_args_key_values("Hello")\r\nshow_args_key_values(first="World")\r\n<\/pre>\nand therefore handle either a list of key\/value set of input.<\/p>\n","protected":false},"excerpt":{"rendered":"
When looking at some built-in functions within builtins.py, I came across the strange syntax def ascii(*args, **kwargs): The *args and **kwargs has a special meaning within Python. The *args will give all function parameters as a tuple and the **kwargs will give a dictionary of key\/values. Note: convention seems to suggest the parameter names args […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[195],"tags":[],"class_list":["post-5746","post","type-post","status-publish","format-standard","hentry","category-python"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/posts\/5746","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/comments?post=5746"}],"version-history":[{"count":3,"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/posts\/5746\/revisions"}],"predecessor-version":[{"id":5753,"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/posts\/5746\/revisions\/5753"}],"wp:attachment":[{"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/media?parent=5746"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/categories?post=5746"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/putridparrot.com\/blog\/wp-json\/wp\/v2\/tags?post=5746"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}