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For 2023 (and 2024 ...) - we are now fully retired from IT training.
We have made many, many friends over 25 years of teaching about Python, Tcl, Perl, PHP, Lua, Java, C and C++ - and MySQL, Linux and Solaris/SunOS too. Our training notes are now very much out of date, but due to upward compatability most of our examples remain operational and even relevant ad you are welcome to make us if them "as seen" and at your own risk.

Lisa and I (Graham) now live in what was our training centre in Melksham - happy to meet with former delegates here - but do check ahead before coming round. We are far from inactive - rather, enjoying the times that we are retired but still healthy enough in mind and body to be active!

I am also active in many other area and still look after a lot of web sites - you can find an index ((here))
Splitting the difference

Perl's split function takes a string of text, and divides it up at a delimiter of your choice into a list of shorter strings ... it's one of the "power tool" functions of Perl and a vital part of the language. So how come that you can write a Tcl program and use its version of split - or omit the split command - and it seems to work either way. Does that seem odd

In Tcl, the split function also turns a string into a list ... it's just that a Tcl list is a string that's formatted with an unprotected space between each list element, which is probably where you started from the in the first place. In other words, the reason you can often include or leave out the call is because in Tcl's case it often does nothing at all!!

Python has two split methods - one that uses an explicit string as the delimiter on which it's to split, and the other in its regular expression class that makes it much more closely akin to the Perl flavour, and in PHP the split function splits at a literal string (you should use preg_split or explode in PHP to split at a regular expression).

Do you ever wonder why I only teach one language per day?

(written 2005-10-13, updated 2011-03-01)

 
Associated topics are indexed as below, or enter http://melksh.am/nnnn for individual articles
Y115 - Additional Python Facilities
  [183] The elegance of Python - (2005-01-19)
  [208] Examples - Gadfly, NI Number, and Tcl to C interface - (2005-02-10)
  [239] What and why for the epoch - (2005-03-08)
  [663] Python to MySQL - (2006-03-31)
  [672] Keeping your regular expressions simple - (2006-04-05)
  [753] Python 3000 - the next generation - (2006-06-09)
  [901] Python - listing out the contents of all variables - (2006-10-21)
  [1043] Sending an email from Python - (2007-01-18)
  [1136] Buffering output - why it is done and issues raised in Tcl, Perl, Python and PHP - (2007-04-06)
  [1149] Turning objects into something you can store - Pickling (Python) - (2007-04-15)
  [1305] Regular expressions made easy - building from components - (2007-08-16)
  [1336] Ignore case in Regular Expression - (2007-09-08)
  [1337] A series of tyre damages - (2007-09-08)
  [1876] Python Regular Expressions - (2008-11-08)
  [2407] Testing code in Python - doctest, unittest and others - (2009-09-16)
  [2435] Serialization - storing and reloading objects - (2009-10-04)
  [2462] Python - how it saves on compile time - (2009-10-20)
  [2655] Python - what is going on around me? - (2010-02-28)
  [2721] Regular Expressions in Python - (2010-04-14)
  [2745] Connecting Python to sqlite and MySQL databases - (2010-04-28)
  [2746] Model - View - Controller demo, Sqlite - Python 3 - Qt4 - (2010-04-29)
  [2764] Python decorators - your own, staticmethod and classmethod - (2010-05-14)
  [2765] Running operating system commands from your Python program - (2010-05-14)
  [2786] Factory methods and SqLite in use in a Python teaching example - (2010-05-29)
  [2790] Joining a MySQL table from within a Python program - (2010-06-02)
  [3089] Python regular expressions - repeating, splitting, lookahead and lookbehind - (2010-12-17)
  [3442] A demonstration of how many Python facilities work together - (2011-09-16)
  [3469] Teaching dilemma - old tricks and techniques, or recent enhancements? - (2011-10-08)
  [4085] JSON from Python - first principles, easy example - (2013-05-13)
  [4211] Handling JSON in Python (and a csv, marshall and pickle comparison) - (2013-11-16)
  [4298] Python - an interesting application - (2014-09-18)
  [4439] Json is the new marshall, pickle and cPickle / Python - (2015-02-22)
  [4451] Running an operating system command from your Python program - the new way with the subprocess module - (2015-03-06)
  [4536] Json load from URL, recursive display, Python 3.4 - (2015-10-14)
  [4593] Command line parameter handling in Python via the argparse module - (2015-12-08)
  [4709] Some gems from Intermediate Python - (2016-10-30)

Y108 - Python - String Handling
  [324] The backtick operator in Python and Perl - (2005-05-25)
  [496] Python printf - (2005-11-15)
  [560] The fencepost problem - (2006-01-10)
  [773] Breaking bread - (2006-06-22)
  [903] Pieces of Python - (2006-10-23)
  [943] Matching within multiline strings, and ignoring case in regular expressions - (2006-11-25)
  [954] Splitting Pythons in Bradford - (2006-11-29)
  [970] String duplication - x in Perl, * in Python and Ruby - (2006-12-07)
  [1110] Python - two different splits - (2007-03-15)
  [1195] Regular Express Primer - (2007-05-20)
  [1517] Python - formatting objects - (2008-01-24)
  [1608] Underlining in Perl and Python - the x and * operator in use - (2008-04-12)
  [2284] Strings as collections in Python - (2009-07-12)
  [2406] Pound Sign in Python Program - (2009-09-15)
  [2692] Flexible search and replace in Python - (2010-03-25)
  [2780] Formatted Printing in Python - (2010-05-25)
  [2814] Python - splitting and joining strings - (2010-06-16)
  [3090] Matching to a string - what if it matches in many possible ways? - (2010-12-17)
  [3218] Matching a license plate or product code - Regular Expressions - (2011-03-28)
  [3349] Formatting output in Python through str.format - (2011-07-07)
  [3468] Python string formatting - the move from % to str.format - (2011-10-08)
  [3796] Backquote, backtic, str and repr in Python - conversion object to string - (2012-07-05)
  [3886] Formatting output - why we need to, and first Python example - (2012-10-09)
  [4027] Collections in Python - list tuple dict and string. - (2013-03-04)
  [4152] Why are bus fares so high? - (2013-08-18)
  [4213] Formatting options in Python - (2013-11-16)
  [4307] Identifying and clearing denial of service attacks on your Apache server - (2014-09-27)
  [4360] Python - comparison of old and new string formatters - (2014-12-22)
  [4595] Python formatting update - including named completions - (2015-12-10)
  [4659] Prining a pound sign from Python AND running from the command line at the same time - (2016-03-03)

T206 - Tcl/Tk - Lists
  [144] Tcl sandwich - lists in Tcl - (2004-12-08)
  [781] Tcl - lappend v concat - (2006-06-27)
  [1282] Stringing together Tcl scripts - (2007-07-29)
  [1283] Generating traffic for network testing - (2007-07-29)
  [1334] Stable sorting - Tcl, Perl and others - (2007-09-06)
  [1402] Tcl - append v lappend v concat - (2007-10-23)
  [1405] Sorting in Tcl - lists and arrays - (2007-10-24)
  [1601] Replacing the last comma with an and - (2008-04-04)
  [2468] What are Tcl lists? - (2009-10-22)
  [2472] split and join in tcl and expect - (2009-10-23)
  [3285] Extracting data from a string / line from file - Tcl - (2011-05-10)
  [3394] The difference between lists and strings - Tcl - (2011-08-16)
  [3415] User defined sorting and other uses of callbacks in Tcl and Tk - (2011-09-02)
  [3582] Tcl collections - lists, dicts and array - (2012-01-16)
  [3583] Expanding a list of parameters in Tcl - {*} and eval - (2012-01-17)
  [3618] lists and struct::list in Tcl - Introduction to struct::list and examples - (2012-02-18)
  [4209] Lists in Tcl - fundamentals in a commented source code example - (2013-11-16)
  [4454] Everything is a string - even a list - (2015-03-11)
  [4455] Working out distance between places, using OS grid references and a program in Tcl - (2015-03-11)

P208 - Perl - Lists
  [28] Perl for breakfast - (2004-08-25)
  [140] Comparison Chart for Perl programmers - list functions - (2004-12-04)
  [230] Course sizes - beware of marketing statistics - (2005-02-27)
  [240] Conventional restraints removed - (2005-03-09)
  [355] Context in Perl - (2005-06-22)
  [622] Queues and barrel rolls in Perl - (2006-02-24)
  [762] Huge data files - what happened earlier? - (2006-06-15)
  [928] C++ and Perl - why did they do it THAT way? - (2006-11-16)
  [968] Perl - a list or a hash? - (2006-12-06)
  [1304] Last elements in a Perl or Python list - (2007-08-16)
  [1316] Filtering and altering Perl lists with grep and map - (2007-08-23)
  [1703] Perl ... adding to a list - end, middle, start - (2008-07-09)
  [1828] Perl - map to process every member of a list (array) - (2008-10-09)
  [1917] Out of memory during array extend - Perl - (2008-12-02)
  [1918] Perl Socket Programming Examples - (2008-12-02)
  [2067] Perl - lists do so much more than arrays - (2009-03-05)
  [2226] Revision / Summary of lists - Perl - (2009-06-10)
  [2295] The dog is not in trouble - (2009-07-17)
  [2484] Finding text and what surrounds it - contextual grep - (2009-10-30)
  [2813] Iterating over a Perl list and changing all items - (2010-06-15)
  [2833] Fresh Perl Teaching Examples - part 2 of 3 - (2010-06-27)
  [2996] Copying - duplicating data, or just adding a name? Perl and Python compared - (2010-10-12)
  [3400] $ is atomic and % and @ are molecular - Perl - (2011-08-20)
  [3548] Dark mornings, dog update, and Python and Lua courses before Christmas - (2011-12-10)
  [3669] Stepping through a list (or an array) in reverse order - (2012-03-23)
  [3870] Writing more maintainable Perl - naming fields from your data records - (2012-09-25)
  [3906] Taking the lead, not the dog, for a walk. - (2012-10-28)
  [3939] Lots of ways of doing the same thing in Perl - list iteration - (2012-12-03)
  [4609] Mapping an array / list without a loop - how to do it in Perl 6 - (2016-01-03)

H107 - String Handling in PHP
  [31] Here documents - (2004-08-28)
  [54] PHP and natural sorting - (2004-09-19)
  [337] the array returned by preg_match_all - (2005-06-06)
  [422] PHP Magic Quotes - (2005-08-22)
  [493] Running a Perl script within a PHP page - (2005-11-12)
  [558] Converting between acres and hectares - (2006-01-08)
  [574] PHP - dividing a string up into pieces - (2006-01-23)
  [589] Robust PHP user inputs - (2006-02-03)
  [608] Don't expose your regular expressions - (2006-02-15)
  [642] How similar are two words - (2006-03-11)
  [716] Evaluating arithmetic expressions in configuration files - (2006-05-10)
  [728] Looking ahead and behind in a Regular Expression - (2006-05-22)
  [1008] Date conversion - PHP - (2006-12-26)
  [1058] PHP Regular expression to extrtact link and text - (2007-01-31)
  [1372] A taster PHP expression ... - (2007-09-30)
  [1533] Short and sweet and sticky - PHP form input - (2008-02-06)
  [1603] Do not SHOUT and do not whisper - (2008-04-06)
  [1613] Regular expression for 6 digits OR 25 digits - (2008-04-16)
  [1799] Regular Expressions in PHP - (2008-09-16)
  [2046] Finding variations on a surname - (2009-02-17)
  [2165] Making Regular Expressions easy to read and maintain - (2009-05-10)
  [2238] Handling nasty characters - Perl, PHP, Python, Tcl, Lua - (2009-06-14)
  [2629] Curly braces within double quoted strings in PHP - (2010-02-09)
  [3020] Handling (expanding) tabs in PHP - (2010-10-29)
  [3424] Divide 10000 by 17. Do you get 588.235294117647, 588.24 or 588? - Ruby and PHP - (2011-09-08)
  [3515] PHP - moving from ereg to preg for regular expressions - (2011-11-11)
  [3516] Regular Expression modifiers in PHP - summary table - (2011-11-12)
  [3534] Learning to program in PHP - Regular Expression and Associative Array examples - (2011-12-01)
  [3788] Getting more than a yes / no answer from a regular expression pattern match - (2012-06-30)
  [3789] More than just matching with a regular expression in PHP - (2012-06-30)
  [3790] Solution looking for a problem? Lookahead and Lookbehind - (2012-06-30)
  [4071] Setting up strings in PHP - (2013-04-27)
  [4072] Splitting the difference with PHP - (2013-04-27)


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Technical Loneliness
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Tell them three times
Separating 'per instance' data from binaries and web sites
Changing Tomcat's web.xml and reloading a web application
Technical Loneliness
Splitting the difference
Big number
Shortened interactive commands
New Network
Kiss and Ride
Final courses of '05 coming up ....
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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.

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