Home Accessibility Courses Twitter The Mouth Facebook Resources Site Map About Us Contact
Looking for a value in a list - Python

In any scripting language, avoiding loops makes for easier to write and faster to run code. One example is Pythons if .. in construct, where you can avoid a loop to test whether a value matches any member of a list or tuple.

Example:

stuff = ["red","green","blue"]
if "green" in stuff: print ("On the grassy field")
if "brown" in stuff: print ("On the muddy soccer pitch")


No need for a loop - just one test and we find that we're in the green stuff and not the brown stuff!

Dorothy:~ grahamellis$ python brst
On the grassy field
Dorothy:~ grahamellis$

(written 2008-09-08)

 
Associated topics are indexed as below, or enter http://melksh.am/nnnn for individual articles
Y104 - Python - Lists and Tuples
  [4027] Collections in Python - list tuple dict and string. - (2013-03-04)
  [3763] Spike solutions and refactoring - a Python example - (2012-06-13)
  [3669] Stepping through a list (or an array) in reverse order - (2012-03-23)
  [3348] List slices in Python - 2 and 3 values forms, with an uplifting example - (2011-07-06)
  [3257] All possible combinations from a list (Python) or array (Ruby) - (2011-04-23)
  [3181] Beware - a=a+b and a+=b are different - Python - (2011-02-23)
  [3118] Arrays of arrays - or 2D arrays. How to program tables. - (2011-01-02)
  [2996] Copying - duplicating data, or just adding a name? Perl and Python compared - (2010-10-12)
  [2719] Traffic lights in Python - (2010-04-13)
  [2368] Python - fresh examples of all the fundamentals - (2009-08-20)
  [2284] Strings as collections in Python - (2009-07-12)
  [2280] Creating and iterating through Python lists - (2009-07-12)
  [1641] Tektronix 4010 series / Python Tuples - (2008-05-13)
  [1220] for loop - how it works (Perl, PHP, Java, C, etc) - (2007-06-06)
  [955] Python collections - mutable and imutable - (2006-11-29)
  [899] Python - extend v append on a list - (2006-10-20)
  [657] The ternary operator in Python - (2006-03-25)
  [383] Overloading of operators on standard objects in Python - (2005-07-19)


Back to
Python 2 to Python 3 / Python 3000 / Py3k
Previous and next
or
Horse's mouth home
Forward to
Sharing variables with functions, but keeping them local too - Python
Some other Articles
Which country does a search engine think you are located in?
All the pieces fall into place - hotel and courses
The road ahead - Python 3
Sharing variables with functions, but keeping them local too - Python
Looking for a value in a list - Python
Python 2 to Python 3 / Python 3000 / Py3k
Howto - write and manage a news box on your web page
Picturing the rain
What is running on your network? (tcl and expect)
Global - Tcl, PHP, Python
4300 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, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86 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).

You can Add a comment or ranking to this page

© WELL HOUSE CONSULTANTS LTD., 2014: Well House Manor • 48 Spa Road • Melksham, Wiltshire • United Kingdom • SN12 7NY
PH: 01144 1225 708225 • FAX: 01144 1225 899360 • EMAIL: info@wellho.net • WEB: http://www.wellho.net • SKYPE: wellho

PAGE: http://www.wellho.net/mouth/1789_Loo ... ython.html • PAGE BUILT: Thu Sep 18 15:30:25 2014 • BUILD SYSTEM: WomanWithCat