2cfd Looking for a value in a list - Python
Training, Open Source Computer Languages

Search for:
Print friendly page
Home Accessibility Courses Diary The Mouth Forum 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 under
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)


57c6
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
4090 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 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
Public Training Courses
Running regularly at our UK training Centre.
[Schedule] - [About] - [Book]

Like this? ??

Related short articles
Python Properties - how and why
Identity in Python
Test Driven Development in Python - Customer Comes First
Quick and easy - showing Python data hander output via a browser
Some tips and techniques for huge data handling in Python
Python network programming - new FTP and socket level examples
Cacheing class for Python - using a local SQLite database as a key/value store
JSON from Python - first principles, easy example
Looking for Creative Design, Catering and Transport inputs to help with Melksham Campus
Exception, Lambda, Generator, Slice, Dict - examples in one Python program
Really Simple Class and Inheritance example in Python
SQL databases from Python - an SQLite example
Spike solution, refactored and reusable, Python - Example
Upcoming courses at Well House Manor - Ruby, Python, Perl
this or self - what are they, and what is the difference? (Python)
vargs in Python - how to call a method with unknown number of parameters
Lots of ways of doing the same thing in Perl - list iteration
Whether you have programmed before or not, we can teach you Python
Multiple identical keys in a Python dict - yes, you can!
Optional positional and named parameters in Python
Reporting the full stack trace when you catch a Python exception
How many times ... has this loco headed west through Tenby? - Python exceptions
How well do you know Perl and / or Python?
Python Programming class for delegates who have already self-taught the basics
Shell - Grep - Sed - Awk - Perl - Python - which to use when?
Inheritance, Composition and Associated objects - when to use which - Python example
Formatting output - why we need to, and first Python example
Default local - a good choice by the author of Python
Chamber of Commerce - looking forward in Melksham and in Wessex
Static variables in Python?
Geekmas 2012 - celebrating open source languages such as Perl, PHP and Python
Know Python or PHP? Want to learn Perl too?
When you should use Object Orientation even in a short program - Python example
zip in Python
Backquote, backtic, str and repr in Python - conversion object to string
Solution looking for a problem? Lookahead and Lookbehind
Melksham Chamber of Commerce - looking to our future shape. Pivotal meeting next Tuesday
Python timing - when to use a list, and when to use a generator
Shell, Awk, Perl of Python?
Learning to program - the if statement. Python.
Looking and Learning - even on Holiday
Splitting a record into individual data values in C
Refresh and Revision training class days - Perl / PHP / Python / Lua / Ruby / Tcl / C / C++
Functions are first class variables in Lua and Python
Object oriented or structured - a comparison in Python. Also writing clean regular expressions
Kings Cross - new concourse - between Python in Cambridge and Objective C in London
Error checking in a Python program - making your program robust via exceptions
Finding all the unique lines in a file, using Python or Perl
Keeping our hotel looking like new, by using our gained experience
Sessions (Shopping Carts) in Django - the Python Web Framework
Sharing lots of values in Tcl without having lots of global declarations
lists and struct::list in Tcl - Introduction to struct::list and examples
The fileutil package and a list of file system commands in Tcl
Looking up
Expanding a list of parameters in Tcl - {*} and eval
Tcl collections - lists, dicts and array
How to do multidimensional arrays (or rather lists and hashes) in Perl
Python or Lua - which should I use / learn?
Football league tables - under old and new point system. Python program.
Some terms used in programming (Biased towards Python)
Dark mornings, dog update, and Python and Lua courses before Christmas
Looking for hotel rooms in Melksham over Christmas? We still have some availability
December courses - PHP, Python, Perl - and a weekend Lua course
Metaclasses (Python) and Metatables (Lua)
Python - current versions and implementations (CPython, Jython, IronPython etc)
Looking forward - Chamber of Commerce has 2012 and beyond on the agenda
Python courses and Private courses - gently updating our product to keep it ahead of the game
Python sets and frozensets - what are they?
Practical Extraction and Reporting - using Python and Extreme Programming
Testing your Python classes with the unittest package - how to
Choosing your Python GUI - wx, Qt, Tk or GTK?
Tkinter - an easy to use Python Graphic User Interface - introductory examples
Python Packages - groupings of modules. An introduction
Python string formatting - the move from % to str.format
How can I do an FTP transfer in Python?
Passing optional and named parameters to python methods
A demonstration of how many Python facilities work together
Pressing ^C in a Python program. Also Progress Bar.
Python for loops - applying a temporary second name to the same object
Moving from scripting to Object Orientation in Python
4a6
© WELL HOUSE CONSULTANTS LTD., 2013: 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: Sat Feb 23 12:39:13 2013 • BUILD SYSTEM: wizard
0