Re: [Tutor] Intermediate/advanced concepts
[EMAIL PROTECTED] wrote on more intermediate/advanced topics like linked lists, nodes, trees, etc. However, it's kind of like reading a math textbook Thats because these are abstract theoretical concepts at the root of programming but not used much in practice in high level languages like Python. If you were using a language like C or Fortran or Pascal they would be highly relevant because the language would not provide much support for collections of data. But Python offers such a wealth of data collections that these advanced topics are largely redundant; just use a list or a dictionary or a set... any suggestions for learning about real world application of more advanced concepts? There are general rules about when different types apply but the edges are blurred in Python. For example a linked list is pretty much a Python list. A double linked list too can often be faked in Python by using negative indexing. Trees are a bit more valid and do have uses in applications like heirarchical data storage such as found in file browsers, family trees, organisational charts etc. They are also very powerful tools for constructing searches of large data sets. Things like bags and sets are just heterogenous collections which Pythons native types mimic well. (Many of these concepts grew out of early languages which only allowed a single type of data in a collection) OTOH there are cases for most of these data types where there are arguments for constructing a dedicated implementation in Python is valid, but they are rare. If you have specific questions about specific types let us know and we can offer more speciofic advice. Also, are there other concepts that I should focus on? Frankly, I'm a bit bored because I've hit this ceiling, and I'm not really sure where to go to next. If you are interested in investigating the more advanced aspects of programming I'd suggest digging into concepts like closures, locking, semaphores, predicate and lambda calculus, boolean algebra, relational data theory, functional programming, aspect oriented programming, literate programming, provable correctness (use of assertions for pre/post conditions and invariance etc), meta data. These are all of more direct relevance in higher level languages like Python. HTH, Alan G. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Intermediate/advanced concepts
On Thu, Nov 6, 2008 at 11:14 PM, [EMAIL PROTECTED] wrote: Hi everyone, I've been teaching myself python for a few months and I'm becoming frustrated because I've kind of hit a wall in terms of learning new information. You might like to read the (printed) Python Cookbook. It has many good examples of idiomatic Python in the context of solving a real problem. Also I suggest you start working on a project that interests you and learn what you need to know to complete it. Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Intermediate/advanced concepts
On Fri, Nov 7, 2008 at 4:12 AM, Eric Abrahamsen [EMAIL PROTECTED]wrote: snip Also, are there other concepts that I should focus on? Frankly, I'm a bit bored because I've hit this ceiling, and I'm not really sure where to go to next. If you want to learn all sorts of new and exciting things, I'd suggest learning about cryptography, and writing attacks (on your own data) as a method of learning more. It's fun, challenging, and there's a real world application for it, if you happen to enjoy any type of security. my 2ยข -Wayne ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Intermediate/advanced concepts
On Nov 7, 2008, at 12:14 PM, [EMAIL PROTECTED] wrote: Hi everyone, I've been teaching myself python for a few months and I'm becoming frustrated because I've kind of hit a wall in terms of learning new information. In an effort to continue to learn I've found some material on more intermediate/advanced topics like linked lists, nodes, trees, etc. However, it's kind of like reading a math textbook - the tutorials do a decent job of explaining the material but it's all kind of theoretical, and I'm not sure how I'd apply these concepts in real world applications, or incorporate them into my code. Does anyone have any suggestions for learning about real world application of more advanced concepts? Are you writing real-world applications and using them? My (admittedly limited) experience has taught me that the real complexities of programming don't lie in obscure data structures or rarely-used functions, but in the practical, real-world issues that arise from creating actual applications: OOP best practices, application architecture, programming paradigms, recurring patterns, even just plain-old programming gotchas (though there are fewer of these in Python than other languages, thankfully). In other words, stuff that isn't necessarily described in the manuals, but that becomes evident once you've made the same mistakes two or three times, and start thinking about modifying your approach to programming. I've never used a tree, and a heap only once, but I feel like I've dipped into some pretty mind-bending stuff in terms of how I've arranged programs. Take metaclasses, for instance: no description of metaclasses I've read ever made sense to me; it only started to come clear after I'd looked at a module I was writing, realized that there was something really fundamentally wrong with it, and then slowly realized that the answer was metaclasses. About eleven lines of metaclass programming, as it turned out, but those seven lines turned my brain inside out for a bit. Not boring in the least! Yrs, Eric Also, are there other concepts that I should focus on? Frankly, I'm a bit bored because I've hit this ceiling, and I'm not really sure where to go to next. Thanks, Ben ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Intermediate/advanced concepts
On Fri, Nov 7, 2008 at 4:12 AM, Alan Gauld [EMAIL PROTECTED] wrote: For example a linked list is pretty much a Python list. Other than the very different timing characteristics! Python lists are O(1) for reading or writing a value at an index, O(n) for inserting and deleting. Linked lists are O(n) for reading and writing and O(1) for insertion and deletion (at a known location). Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Intermediate/advanced concepts
On Thu, 06 Nov 2008 23:14:38 -0500, btkuhn wrote: Hi everyone, I've been teaching myself python for a few months and I'm becoming frustrated because I've kind of hit a wall in terms of learning new information. In an effort to continue to learn I've found some material on more intermediate/advanced topics like linked lists, nodes, trees, etc. However, it's kind of like reading a math textbook - the tutorials do a decent job of explaining the material but it's all kind of theoretical, and I'm not sure how I'd apply these concepts in real world applications, or incorporate them into my code. Does anyone have any suggestions for learning about real world application of more advanced concepts? Also, are there other concepts that I should focus on? Frankly, I'm a bit bored because I've hit this ceiling, and I'm not really sure where to go to next. There is really no ceiling in learning programming. The problem is to find a problem. If you're bored, you can do the practically-for-bored- programmers challenges like Python Challenge (http:// www.pythonchallenge.com/) or Project Euler (http://projecteuler.net/ index.php?section=view) If you're up to the challenge and responsibility, you could join an open source program teams or start one yourself. Alternatively, you could also start learning some embedded python flavors, like the one used by OpenOffice.org or Inkscape, these provides different challenge to vanilla python as you've got to learn their libraries. If you think you're bored of python, perhaps it is time to start learning another language. Having many programming language in your toolbox is certainly a life-saver, since some problems are easier to solve in certain languages than other. For example, many mathematical problems are (much) easier to express in functional language, like Haskell, compared to imperative language. Other languages might have features/paradigm that are foreign in python, like Eiffel's Programming by Contract. You might also start seeing domain-specific languages, like SQL (database), XSLT (XML), (E)BNF (syntax parsing), etc. Alternative languages you might consider: Haskell, Prolog, Eiffel, C- family, Perl, Lisp-family, APL-family, some assembly, shell scripting (bash, bat, etc) If you're EXTREMELY bored though, you might learn some of the more esoteric languages, e.g. Shakespeare, Piet, Whitespace, etc (be ready to abandon all sanity) ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Intermediate/advanced concepts
Kent Johnson [EMAIL PROTECTED] wrote For example a linked list is pretty much a Python list. Other than the very different timing characteristics! True, but its pretty rare that timing issues are a reason for me to choose a data structure - especially if I need to hand code it! :-) Python lists are O(1) for reading or writing a value at an index, O(n) for inserting and deleting. Linked lists are O(n) for reading and writing and O(1) for insertion and deletion (at a known location). I would say O(1) only if you already have a reference to that location (ie its known in that sense) but if you know that it's at position 23 but you only have a reference to the head you still need to navigate sequentially to the 23rd element so its still an O(n). O(1) only applies when inserting at the next position to where you currently are. That's not too common a scenario in my experience. But the geneal point is a good specific example (and I was struggling to think of one!) where you might choose a non standard list over the vanilla version. The array module is another case where performance is improved over the standard lists. Alan G. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Intermediate/advanced concepts
On Fri, Nov 7, 2008 at 6:16 PM, Alan Gauld [EMAIL PROTECTED] wrote: True, but its pretty rare that timing issues are a reason for me to choose a data structure I would guess you commonly choose a dict or set over a list when you need fast tests for membership. Failure to choose dict when appropriate is certainly a common cause of performance problems. But the geneal point is a good specific example (and I was struggling to think of one!) where you might choose a non standard list over the vanilla version. The array module is another case where performance is improved over the standard lists. The standard lib also includes collections.deque (O(1) insertion and deletion at both ends) and heapq (binary priority queue). Third party implementations of b-tree, avltree and trie are available which have better performance than list and dict for some usage. Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Intermediate/advanced concepts
Hi everyone, I've been teaching myself python for a few months and I'm becoming frustrated because I've kind of hit a wall in terms of learning new information. In an effort to continue to learn I've found some material on more intermediate/advanced topics like linked lists, nodes, trees, etc. However, it's kind of like reading a math textbook - the tutorials do a decent job of explaining the material but it's all kind of theoretical, and I'm not sure how I'd apply these concepts in real world applications, or incorporate them into my code. Does anyone have any suggestions for learning about real world application of more advanced concepts? Also, are there other concepts that I should focus on? Frankly, I'm a bit bored because I've hit this ceiling, and I'm not really sure where to go to next. Thanks, Ben ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
