Training, Open Source computer languages

PerlPHPPythonMySQLhttpd / TomcatTclRubyJavaC and C++LinuxCSS

Search our site for:
Home Accessibility Courses Diary The Mouth Forum Resources Site Map About Us Contact
Function / method parameters with * and ** in Python
In Python, you can define a function with optional parameters; if you specify a single * in front of a parameter, then that will be a tuple of all remaining unnamed values. And if you specify two *s in front of a parameter, that will be a dictionary of all remaining named parameters.

Let's see an example:

def demo(first, second, *third, **fourth):
  print "first",first
  print "second",second
  print "third",third
  print "fourth",fourth
  print
 
demo(1,2,3,4,5,6,7)
 
demo(5,6,7,8,aa=9,bb=11,cc=44)


When I run that, I get

C:\gje>python onetwo.py
first 1
second 2
third (3, 4, 5, 6, 7)
fourth {}
 
first 5
second 6
third (7, 8)
fourth {'aa': 9, 'cc': 44, 'bb': 11}
 
C:\gje>


Note that * and ** parameters must be the last parameters in a function definition, and if you're going to use both of them you put the ** at the very end, after the *.
(written 2007-04-04 00:39:41)

 
Associated topics are indexed under
Y105 - Python - Functions, Modules and Packages

Back to
B-2-B Networking, 20th April. Useful for YOUR business?
Previous and next
or
Horse's mouth home
Forward to
Government pressure on me to shut up after I make the papers

Some other Articles
The Holiday - unlikely romantic comedy?
Wiltshire Circles
Buffering output - why it is done and issues raised in Tcl, Perl, Python and PHP
Government pressure on me to shut up after I make the papers
Function / method parameters with * and ** in Python
B-2-B Networking, 20th April. Useful for YOUR business?
Well House Manor, Melksham, Art Gallery
MySQL - Password security (authentication protocol)
Science Museum - larger exhibits / store, Wroughton, Swindon
Golfing, Wiltshire (near Melksham)
1635 posts, page by page
Link to page ... 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33 at 50 posts per page


This is a page archived from The Horse's Mouth at http://www.wellho.net/horse/ - the diary and writings of Graham Ellis. Every attempt was made to provide current information at the time the page was written, but things do move forward in our business - new software releases, price changes, new techniques. Please check back via our main site for current courses, prices, versions, etc - any mention of a price in "The Horse's Mouth" cannot be taken as an offer to supply at that price.

Link to Ezine home page (for reading).
Link to Blogging home page (to add comments).

© WELL HOUSE CONSULTANTS LTD., 2008: Well House Manor • 48 Spa Road • Melksham, Wiltshire • United Kingdom • SN12 7NY
PH: 01144 1225 708225 • FAX: 01144 1225 707126 • EMAIL: info@wellho.net • WEB: http://www.wellho.net • SKYPE: wellho