Related
I'm looking at this question Python: give start and end of week data from a given date. It seems most people prefer using standard libraries instead of going for something like pendulum which seems to be much easier to use and readable in terms of code.
How do I think about the trade offs on what to choose when deciding on what approach to take? My main objective is to code once and not have to update the code ever again. This going from 2.7 to 3.x is really a pain to update my whole code base. It seems like I should always use standard library unless the library saves me tons of time.
Can a more experienced programmer comment on this?
So I've been self-learning Python through this app and I've gotten through the course it offers. I feel like I have a good grasp on the absolute basics of the language, but I still have no idea how to actually use it to solve real problems, ie do actually useful things. I feel like I have a bunch of building blocks but I don't know how to put them together.
So enter my job. I'm a student that works part time and we do weekly schedule requests by paper. It's a giant pain for both us and the supervisors who do the actual scheduling. I was thinking it might be cool to write something to automate the process. It's not so much about the end product though, I'm not being paid enough to write software for my employer. I've just heard everywhere that actually working on projects is the best way to learn and I'm taking this real problem as an opportunity to practice.
So my question is, where should I go from my bare bones knowledge of Python to be able to write something like this? Do I read books? Learn about fancy algorithms? Find something similar and browse its source code? Thanks!
First, you need to figure out what you want to your program to do, specifically. Programs are ways to automate processes, and you can not automate something until you know what the process is. You are trying to solve a real-world problem, the first thing you need to do is figure out how this problem is solved today (without your program).
When you try to figure this out, you should not be thinking about how to actually code it in Python, but rather what stepds need to be taken (manually) to achieve what you want. Exactly what would you do if you were doing the scheduling by hand?
Often, people find it useful to describe what a system is actually supposed to do via use cases. A use case would describe a single function, feature or process from the perspective of a user of your system. Of course, you don't need to formally write uses cases for your system, but it might help to think of what the system should be doing from a user's perspectice before thinking of the technical details to achieve this.
Once you have concrete features, processes or steps the program need to support, you can start digging into how to actually implement this in Python.
Recently i have developed a billing application for my company with Python/Django. For few months everything was fine but now i am observing that the performance is dropping because of more and more users using that applications. Now the problem is that the application is now very critical for the finance team. Now the finance team are after my life for sorting out the performance issue. I have no other option but to find a way to increase the performance of the billing application.
So do you guys know any performance optimization techniques in python that will really help me with the scalability issue
Guys we are using mysql database and its hosted on apache web server on Linux box. Secondly what i have noticed more is the over all application is slow and not the database transactional part. For example once the application is loaded then it works fine but if they navigate to other link on that application then it takes a whole lot of time.
And yes we are using HTML, CSS and Javascript
As I said in comment, you must start by finding what part of your code is slow.
Nobody can help you without this information.
You can profile your code with the Python profilers then go back to us with the result.
If it's a Web app, the first suspect is generally the database. If it's a calculus intensive GUI app, then look first at the calculations algo first.
But remember that perf issues car be highly unintuitive and therefor, an objective assessment is the only way to go.
ok, not entirely to the point, but before you go and start fixing it, make sure everyone understands the situation. it seems to me that they're putting some pressure on you to fix the "problem".
well first of all, when you wrote the application, have they specified the performance requirements? did they tell you that they need operation X to take less than Y secs to complete? Did they specify how many concurrent users must be supported without penalty to the performance? If not, then tell them to back off and that it is iteration (phase, stage, whatever) one of the deployment, and the main goal was the functionality and testing. phase two is performance improvements. let them (with your help obviously) come up with some non functional requirements for the performance of your system.
by doing all this, a) you'll remove the pressure applied by the finance team (and i know they can be a real pain in the bum) b) both you and your clients will have a clear idea of what you mean by "performance" c) you'll have a base that you can measure your progress and most importantly d) you'll have some agreed time to implement/fix the performance issues.
PS. that aside, look at the indexing... :)
A surprising feature of Python is that the pythonic code is quite efficient... So a few general hints:
Use built-ins and standard functions whenever possible, they're already quite well optimized.
Try to use lazy generators instead one-off temporary lists.
Use numpy for vector arithmetic.
Use psyco if running on x86 32bit.
Write performance critical loops in a lower level language (C, Pyrex, Cython, etc.).
When calling the same method of a collection of objects, get a reference to the class function and use it, it will save lookups in the objects dictionaries (this one is a micro-optimization, not sure it's worth)
And of course, if scalability is what matters:
Use O(n) (or better) algorithms! Otherwise your system cannot be linearly scalable.
Write multiprocessor aware code. At some point you'll need to throw more computing power at it, and your software must be ready to use it!
before you can "fix" something you need to know what is "broken". In software development that means profiling, profiling, profiling. Did I mention profiling. Without profiling you don't know where CPU cycles and wall clock time is going. Like others have said to get any more useful information you need to post the details of your entire stack. Python version, what you are using to store the data in (mysql, postgres, flat files, etc), what web server interface cgi, fcgi, wsgi, passenger, etc. how you are generating the HTML, CSS and assuming Javascript. Then you can get more specific answers to those tiers.
You may be interested in this document I've found some time ago.
As personal advice, be as more pythonic as you can: lazy evaluation is the keyword, so learn to use iterators and generators.
For the type of application you are describing (a web application probably backed by a database) your performance problems are unlikely to be language specific. They are far more likely to stem from design or architecture issues, though they could be simple coding problems too.
To sort this out you need to figure out where the bottlenecks are in your application and for that you need some sort of profiler.
Once you have found your bottlenecks you will be in a much better position. You can evaluate then problem areas for common issues including:
Design and Architecture issues
SQL anti-patterns
Incorrect usage of your framework (perhaps relying on inappropriate defaults)
Badly structured algorithms
The specifics of any solution are going to depend on the specifics of the bottlenecks your find.
http://wiki.python.org/moin/PythonSpeed/PerformanceTips
I optimized some python code a while back, the most surprising thing to me was how much each function call costs. If you minimize function calls or replace loops with builtins you'll be running much faster.
There are some great suggestions here… So let me suggest an implementation detail. I have found the runprofileserver command found in django-command-extensions very convenient for profiling my Django code.
I am not sure if this would solve the problem but you should have a look at psyco
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I've been learning, working, and playing with Python for a year and a half now. As a biologist slowly making the turn to bio-informatics, this language has been at the very core of all the major contributions I have made in the lab. I more or less fell in love with the way Python permits me to express beautiful solutions and also with the semantics of the language that allows such a natural flow from thoughts to workable code.
What I would like to know is your answer to a kind of question I have seldom seen in this or other forums. This question seems central to me for anyone on the path to Python improvement but who wonders what his next steps should be.
Let me sum up what I do NOT want to ask first ;)
I don't want to know how to QUICKLY learn Python
Nor do I want to find out the best way to get acquainted with the language
Finally, I don't want to know a 'one trick that does it all' approach.
What I do want to know your opinion about, is:
What are the steps YOU would recommend to a Python journeyman, from apprenticeship to guru status (feel free to stop wherever your expertise dictates it), in order that one IMPROVES CONSTANTLY, becoming a better and better Python coder, one step at a time. Some of the people on SO almost seem worthy of worship for their Python prowess, please enlighten us :)
The kind of answers I would enjoy (but feel free to surprise the readership :P ), is formatted more or less like this:
Read this (eg: python tutorial), pay attention to that kind of details
Code for so manytime/problems/lines of code
Then, read this (eg: this or that book), but this time, pay attention to this
Tackle a few real-life problems
Then, proceed to reading Y.
Be sure to grasp these concepts
Code for X time
Come back to such and such basics or move further to...
(you get the point :)
I really care about knowing your opinion on what exactly one should pay attention to, at various stages, in order to progress CONSTANTLY (with due efforts, of course). If you come from a specific field of expertise, discuss the path you see as appropriate in this field.
EDIT: Thanks to your great input, I'm back on the Python improvement track! I really appreciate!
I thought the process of Python mastery went something like:
Discover list comprehensions
Discover generators
Incorporate map, reduce, filter, iter, range, xrange often into your code
Discover Decorators
Write recursive functions, a lot
Discover itertools and functools
Read Real World Haskell (read free online)
Rewrite all your old Python code with tons of higher order functions, recursion, and whatnot.
Annoy your cubicle mates every time they present you with a Python class. Claim it could be "better" implemented as a dictionary plus some functions. Embrace functional programming.
Rediscover the Strategy pattern and then all those things from imperative code you tried so hard to forget after Haskell.
Find a balance.
One good way to further your Python knowledge is to dig into the source code of the libraries, platforms, and frameworks you use already.
For example if you're building a site on Django, many questions that might stump you can be answered by looking at how Django implements the feature in question.
This way you'll continue to pick up new idioms, coding styles, and Python tricks. (Some will be good and some will be bad.)
And when you see something Pythony that you don't understand in the source, hop over to the #python IRC channel and you'll find plenty of "language lawyers" happy to explain.
An accumulation of these little clarifications over years leads to a much deeper understanding of the language and all of its ins and outs.
Understand (more deeply) Python's data types and their roles with regards to memory mgmt
As some of you in the community are aware, I teach Python courses, the most popular ones being the comprehensive Intro+Intermediate course as well as an "advanced" course which introduces a variety of areas of application development.
Quite often, I get asked a question quite similar to, "Should I take your intro or advanced course? I've already been programming Python for 1-2 years, and I think the intro one is too simple for me so I'd like to jump straight to the advanced... which course would you recommend?"
To answer their question, I probe to see how strong they are in this area -- not that it's really the best way to measure whether they're ready for any advanced course, but to see how well their basic knowledge is of Python's objects and memory model, which is a cause of many Python bugs written by those who are not only beginners but those who have gone beyond that.
To do this, I point them at this simple 2-part quiz question:
Many times, they are able to get the output, but the why is more difficult and much more important of an response... I would weigh the output as 20% of the answer while the "why" gets 80% credit. If they can't get the why, regardless how Python experience they have, I will always steer people to the comprehensive intro+intermediate course because I spend one lecture on objects and memory management to the point where you should be able to answer with the output and the why with sufficient confidence. (Just because you know Python's syntax after 1-2 years doesn't make you ready to move beyond a "beginner" label until you have a much better understanding as far as how Python works under the covers.)
A succeeding inquiry requiring a similar answer is even tougher, e.g.,
Example 3
x = ['foo', [1,2,3], 10.4]
y = list(x) # or x[:]
y[0] = 'fooooooo'
y[1][0] = 4
print x
print y
The next topics I recommend are to understanding reference counting well, learning what "interning" means (but not necessarily using it), learning about shallow and deep copies (as in Example 3 above), and finally, the interrelationships between the various types and constructs in the language, i.e. lists vs. tuples, dicts vs. sets, list comprehensions vs. generator expressions, iterators vs. generators, etc.; however all those other suggestions are another post for another time. Hope this helps in the meantime! :-)
ps. I agree with the other responses for getting more intimate with introspection as well as studying other projects' source code and add a strong "+1" to both suggestions!
pps. Great question BTW. I wish I was smart enough in the beginning to have asked something like this, but that was a long time ago, and now I'm trying to help others with my many years of full-time Python programming!!
Check out Peter Norvig's essay on becoming a master programmer in 10 years: http://norvig.com/21-days.html. I'd wager it holds true for any language.
Understand Introspection
write a dir() equivalent
write a type() equivalent
figure out how to "monkey-patch"
use the dis module to see how various language constructs work
Doing these things will
give you some good theoretical knowledge about how python is implemented
give you some good practical experience in lower-level programming
give you a good intuitive feel for python data structures
def apprentice():
read(diveintopython)
experiment(interpreter)
read(python_tutorial)
experiment(interpreter, modules/files)
watch(pycon)
def master():
refer(python-essential-reference)
refer(PEPs/language reference)
experiment()
read(good_python_code) # Eg. twisted, other libraries
write(basic_library) # reinvent wheel and compare to existing wheels
if have_interesting_ideas:
give_talk(pycon)
def guru():
pass # Not qualified to comment. Fix the GIL perhaps?
I'll give you the simplest and most effective piece of advice I think anybody could give you: code.
You can only be better at using a language (which implies understanding it) by coding. You have to actively enjoy coding, be inspired, ask questions, and find answers by yourself.
Got a an hour to spare? Write code that will reverse a string, and find out the most optimum solution. A free evening? Why not try some web-scraping. Read other peoples code. See how they do things. Ask yourself what you would do.
When I'm bored at my computer, I open my IDE and code-storm. I jot down ideas that sound interesting, and challenging. An URL shortener? Sure, I can do that. Oh, I learnt how to convert numbers from one base to another as a side effect!
This is valid whatever your skill level. You never stop learning. By actively coding in your spare time you will, with little additional effort, come to understand the language, and ultimately, become a guru. You will build up knowledge and reusable code and memorise idioms.
If you're in and using python for science (which it seems you are) part of that will be learning and understanding scientific libraries, for me these would be
numpy
scipy
matplotlib
mayavi/mlab
chaco
Cython
knowing how to use the right libraries and vectorize your code is essential for scientific computing.
I wanted to add that, handling large numeric datasets in common pythonic ways(object oriented approaches, lists, iterators) can be extremely inefficient. In scientific computing, it can be necessary to structure your code in ways that differ drastically from how most conventional python coders approach data.
Google just recently released an online Python class ("class" as in "a course of study").
http://code.google.com/edu/languages/google-python-class/
I know this doesn't answer your full question, but I think it's a great place to start!
Download Twisted and look at the source code. They employ some pretty advanced techniques.
Thoroughly Understand All Data Types and Structures
For every type and structure, write a series of demo programs that exercise every aspect of the type or data structure. If you do this, it might be worthwhile to blog notes on each one... it might be useful to lots of people!
I learned python first by myself over a summer just by doing the tutorial on the python site (sadly, I don't seem to be able to find that anymore, so I can't post a link).
Later, python was taught to me in one of my first year courses at university. In the summer that followed, I practiced with PythonChallenge and with problems from Google Code Jam.
Solving these problems help from an algorithmic perspective as well as from the perspective of learning what Python can do as well as how to manipulate it to get the fullest out of python.
For similar reasons, I have heard that code golf works as well, but i have never tried it for myself.
Learning algorithms/maths/file IO/Pythonic optimisation
This won't get you guru-hood but to start out, try working through the Project Euler problems
The first 50 or so shouldn't tax you if you have decent high-school mathematics and know how to Google. When you solve one you get into the forum where you can look through other people's solutions which will teach you even more. Be decent though and don't post up your solutions as the idea is to encourage people to work it out for themselves.
Forcing yourself to work in Python will be unforgiving if you use brute-force algorithms.
This will teach you how to lay out large datasets in memory and access them efficiently with the fast language features such as dictionaries.
From doing this myself I learnt:
File IO
Algorithms and techniques such as Dynamic Programming
Python data layout
Dictionaries/hashmaps
Lists
Tuples
Various combinations thereof, e.g. dictionaries to lists of tuples
Generators
Recursive functions
Developing Python libraries
Filesystem layout
Reloading them during an interpreter session
And also very importantly
When to give up and use C or C++!
All of this should be relevant to Bioinformatics
Admittedly I didn't learn about the OOP features of Python from that experience.
Have you seen the book "Bioinformatics Programming using Python"? Looks like you're an exact member of its focus group.
You already have a lot of reading material, but if you can handle more, I recommend you
learn about the evolution of python by reading the Python Enhancement Proposals, especially the "Finished" PEPs and the "Deferred, Abandoned, Withdrawn, and Rejected" PEPs.
By seeing how the language has changed, the decisions that were made and their rationales, you will absorb the philosophy of Python and understand how "idiomatic Python" comes about.
http://www.python.org/dev/peps/
Attempt http://challenge.greplin.com/ using Python
Teaching to someone else who is starting to learn Python is always a great way to get your ideas clear and sometimes, I usually get a lot of neat questions from students that have me to re-think conceptual things about Python.
Not precisely what you're asking for, but I think it's good advice.
Learn another language, doesn't matter too much which. Each language has it's own ideas and conventions that you can learn from. Learn about the differences in the languages and more importantly why they're different. Try a purely functional language like Haskell and see some of the benefits (and challenges) of functions free of side-effects. See how you can apply some of the things you learn from other languages to Python.
I recommend starting with something that forces you to explore the expressive power of the syntax. Python allows many different ways of writing the same functionality, but there is often a single most elegant and fastest approach. If you're used to the idioms of other languages, you might never otherwise find or accept these better ways. I spent a weekend trudging through the first 20 or so Project Euler problems and made a simple webapp with Django on Google App Engine. This will only take you from apprentice to novice, maybe, but you can then continue to making somewhat more advanced webapps and solve more advanced Project Euler problems. After a few months I went back and solved the first 20 PE problems from scratch in an hour instead of a weekend.
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Original Question
I am currently engaged in teaching my brother to program. He is a total beginner, but very smart. (And he actually wants to learn). I've noticed that some of our sessions have gotten bogged down in minor details, and I don't feel I've been very organized. (But the answers to this post have helped a lot.)
What can I do better to teach him effectively? Is there a logical order that I can use to run through concept by concept? Are there complexities I should avoid till later?
The language we are working with is Python, but advice in any language is welcome.
How to Help
If you have good ones please add the following in your answer:
Beginner Exercises and Project Ideas
Resources for teaching beginners
Screencasts / blog posts / free e-books
Print books that are good for beginners
Please describe the resource with a link to it so I can take a look. I want everyone to know that I have definitely been using some of these ideas. Your submissions will be aggregated in this post.
Online Resources for teaching beginners:
A Gentle Introduction to Programming Using Python
How to Think Like a Computer Scientist
Alice: a 3d program for beginners
Scratch (A system to develop programming skills)
How To Design Programs
Structure and Interpretation of Computer Programs
Learn To Program
Robert Read's How To Be a Programmer
Microsoft XNA
Spawning the Next Generation of Hackers
COMP1917 Higher Computing lectures by Richard Buckland (requires iTunes)
Dive into Python
Python Wikibook
Project Euler - sample problems (mostly mathematical)
pygame - an easy python library for creating games
Invent Your Own Computer Games With Python
Foundations of Programming for a next step beyond basics.
Squeak by Example
Snake Wrangling For Kids (It's not just for kids!)
Recommended Print Books for teaching beginners
Accelerated C++
Python Programming for the Absolute Beginner
Code by Charles Petzold
Python Programming: An Introduction to Computer Science 2nd Edition
I've had to work with several beginner (never wrote a line of code) programmers, and I'll be doing an after school workshop with high school students this fall. This is the closest thing I've got to documentation. It's still a work in progress, but I hope it helps.
1) FizzBuzz. Start with command line programs. You can write some fun games, or tools, very quickly, and you learn all of the language features very quickly without having to learn the GUI tools first. These early apps should be simple enough that you won't need to use any real debugging tools to make them work.
If nothing else things like FizzBuzz are good projects. Your first few apps should not have to deal with DBs, file system, configuration, ect. These are concepts which just confuse most people, and when you're just learning the syntax and basic framework features you really don't need more complexity.
Some projects:
Hello World!
Take the year of my birth, and calculate my age (just (now - then) no month corrections). (simple math, input, output)
Ask for a direction(Up, down, left, right), then tell the user their fate (fall in a hole, find a cake, ect). (Boolean logic)
FizzBuzz, but count once every second. (Loops, timers, and more logic)
Depending on their age some really like an app which calls the users a random insult at some interval. (Loops, arrays, timers, and random if you make the interval random)
2) Simple Project Once they have a good grasp of language features, you can start a project(simple, fun games work good.). You should try to have the first project be able to be completed within 6-12 hours. Don't spend time to architect it early. Let them design it even if it sucks. If it falls apart, talk about what happened and why it failed, then pick another topic and start again.
This is where you start introducing the debugging capabilities of your tools. Even if you can see the problem by reading the code you should teach them how to use the tools, and then show them how you could see it. That serves the dual purpose of teaching the debugging tools and teaching how to ID errors without tools.
Once, or if, the project gets functional you can use it to introduce refactoring tools. Its good if you can then expand the project with some simple features which you never planned for. This usually means refactoring and significant debugging, since very few people write even half decent code their first time.
Some projects:
Hangman game
Experimenting with robotics(Vex and Mindstorms are options)
3) Real Project Start a real project which may take some time. Use proper source control, and make a point to have a schedule. Run this project like a real project, if nothing else its good experience having to deal with the tools.
Obviously you need to adjust this for each person. The most important thing I've found is to make even the first simple apps apply to what the person is interested in.
Some projects:
Tetris
Text file based blog engine
More advanced robotics work
You could try using Alice. It's a 3D program designed for use in introductory programming classes.
The two biggest obstacles for new programmers are often:
syntax errors
motivation (writing something meaningful and fun rather than contrived)
Alice uses a drag and drop interface for constructing programs, avoiding the possibility of syntax errors. Alice lets you construct 3D worlds and have your code control (simple) 3D characters and animation, which is usually a lot more interesting than implementing linked lists.
Experienced programmers may look down at Alice as a toy and scoff at dragging and dropping lines of code, but research shows that this approach works.
Disclaimer: I worked on Alice.
I recommend Logo (aka the turtle) to get the basic concepts down. It provides a good sandbox with immediate graphical feedback, and you can demostrate loops, variables, functions, conditionals, etc. This page provides an excellent tutorial.
After Logo, move to Python or Ruby. I recommend Python, as it's based on ABC, which was invented for the purpose of teaching programming.
When teaching programming, I must second EHaskins's suggestion of simple projects and then complex projects. The best way to learn is to start with a definite outcome and a measurable milestone. It keeps the lessons focused, allows the student to build skills and then build on those skills, and gives the student something to show off to friends. Don't underestimate the power of having something to show for one's work.
Theoretically, you can stick with Python, as Python can do almost anything. It's a good vehicle to teach object-oriented programming and (most) algorithms. You can run Python in interactive mode like a command line to get a feel for how it works, or run whole scripts at once. You can run your scripts interpreted on the fly, or compile them into binaries. There are thousands of modules to extend the functionality. You can make a graphical calculator like the one bundled with Windows, or you can make an IRC client, or anything else.
XKCD describes Python's power a little better:
You can move to C# or Java after that, though they don't offer much that Python doesn't already have. The benefit of these is that they use C-style syntax, which many (dare I say most?) languages use. You don't need to worry about memory management yet, but you can get used to having a bit more freedom and less handholding from the language interpreter. Python enforces whitespace and indenting, which is nice most of the time but not always. C# and Java let you manage your own whitespace while remaining strongly-typed.
From there, the standard is C or C++. The freedom in these languages is almost existential. You are now in charge of your own memory management. There is no garbage collection to help you. This is where you teach the really advanced algorithms (like mergesort and quicksort). This is where you learn why "segmentation fault" is a curse word. This is where you download the source code of the Linux kernel and gaze into the Abyss. Start by writing a circular buffer and a stack for string manipulation. Then work your way up.
A good python course is MIT's A Gentle Introduction to Programming Using Python. It's all free online, and you don't have to be an MIT uberstudent to understand it.
Edit [Justin Standard]
This course uses this free online book: How To Think Like a Computer Scientist
I'm definitely finding it quite useful.
Python package VPython -- 3D Programming for Ordinary Mortal (video tutorial).
Code example:
from visual import *
floor = box (pos=(0,0,0), length=4, height=0.5, width=4, color=color.blue)
ball = sphere (pos=(0,4,0), radius=1, color=color.red)
ball.velocity = vector(0,-1,0)
dt = 0.01
while 1:
rate (100)
ball.pos = ball.pos + ball.velocity*dt
if ball.y < ball.radius:
ball.velocity.y = -ball.velocity.y
else:
ball.velocity.y = ball.velocity.y - 9.8*dt
VPython bouncing ball http://vpython.org/bounce.gif
Begin with Turtle graphics in Python.
I would use the turtle graphics which comes standard with Python. It is visual, simple and you could use this environment to introduce many programming concepts like iteration and procedure calls before getting too far into syntax. Consider the following interactive session in python:
>>> from turtle import *
>>> setup()
>>> title("turtle test")
>>> clear()
>>>
>>> #DRAW A SQUARE
>>> down() #pen down
>>> forward(50) #move forward 50 units
>>> right(90) #turn right 90 degrees
>>> forward(50)
>>> right(90)
>>> forward(50)
>>> right(90)
>>> forward(50)
>>>
>>> #INTRODUCE ITERATION TO SIMPLIFY SQUARE CODE
>>> clear()
>>> for i in range(4):
forward(50)
right(90)
>>>
>>> #INTRODUCE PROCEDURES
>>> def square(length):
down()
for i in range(4):
forward(length)
right(90)
>>>
>>> #HAVE STUDENTS PREDICT WHAT THIS WILL DRAW
>>> for i in range(50):
up()
left(90)
forward(25)
square(i)
>>>
>>> #NOW HAVE THE STUDENTS WRITE CODE TO DRAW
>>> #A SQUARE 'TUNNEL' (I.E. CONCENTRIC SQUARES
>>> #GETTING SMALLER AND SMALLER).
>>>
>>> #AFTER THAT, MAKE THE TUNNEL ROTATE BY HAVING
>>> #EACH SUCCESSIVE SQUARE TILTED
In trying to accomplish the last two assignments, they will have many failed attempts, but the failures will be visually interesting and they'll learn quickly as they try to figure out why it didn't draw what they expected.
The key thing is that the person in question needs to have some problem that they want solving. If you don't have a program that you want to write (and something sensible and well-defined, not "I want to write the next Quake!") then you can't learn to program, because you have nothing to motivate you. I mean, you could read a book and have a rough understanding of a language's syntax and semantics, but until you have a program that you want written you'll never grasp the nettle.
If that impetus exists then everything else is just minor details.
I don't know if anyone has mentioned this here, yet, but You might want to check out Zed Shaw's Learn Python the Hard Way
Hope this Helps
http://tryruby.hobix.com/">Try Ruby (In Your Browser)
How to Design Programs
Structure and Interpretation of Computer Programs . Videos lectures at http://www.swiss.ai.mit.edu/classes/6.001/abelson-sussman-lectures/
This is a fantastic book which my little brothers used to learn:
http://pine.fm/LearnToProgram/
Of course, the most important thing is to start on a real, useful program of some kind IMMEDIATELY after finishing the book.
If he's interested, aren't the minor details the good parts? Using python, you've already cut the GUI off of it so that confusion is gone. Why not pick a project, a game or something, and implement it. The classic hi-lo number guessing game can be simply implemented from the command line in 20-30 lines of code (depending on language of course) and gives you variables, conditions, loops, and user input.
I'd just let him write tons of code. Let him drive in everything you guys do, and just be available to answer questions.
Believe it or not, after a few months of writings tons of crappy code, he'll start to get the idea and start writing better programs. At that point, you can get bogged down in details (memory, etc), and also talk about general design principles.
I've heard that what separates the great artists from the mediocre ones, is that every time they practice, they improve on something, no matter how small. Let your brother practice, and he'll improve every time he sits down at the keyboard.
Edit: [Justin Standard]
Esteban, this reminds me of a recent coding horror post, and I do think you are right. But I think its still worthwhile to find methods to guide his practice. No question, I want him writing as much code as he knows how to do. Thats one reason I'm asking for sample projects.
First of all, start out like everyone else does: with a Hello World program. It's simple, and it gives them a basic feel for the layout of a program. Try and remember back to when you were first programming, and how difficult some of the concepts were - start simple.
After Hello World, move on to creating some basic variables, arithmetic, then onto boolean logic and if/else statements. If you've got one of your old programming textbooks, check out some of the early examples and have him run through those. Just don't try to introduce too much all at once, or it will be overwhelming and confusing.
Something you should be very mindful of while teaching your brother to program is for him not to rely too heavily on you. Often when I find myself helping others they will begin to think of me as answer book to all of their questions and instead of experimenting to find an answer they simply ask me. Often the best teacher is experimentation and every time your brother has a question like "What will happen if I add 2 to a string?" you should tell him to try it out and see for himself. Also I have noticed that when I cannot get a concept through to someone, it helps to see some sample code where we can look at each segment individually and explain it piece by piece. As a side note people new to programming often have trouble with the idea of object oriented programming, they will say they understand it when you teach it to them but will not get a clear concept of it until actually implementing it.
I used to teach programming and your brother has one main advantage over most of my students he wants to learn :)
If you decide to go with C a friend has a site that has the sort of programs those of use from older generations remember as basic type-ins. The more complex of them use ncurses which sort of negates their use as a teaching aid somewhat but some of them are tiny little things and you can learn loads without being taught to.
Personally I think Python and Ruby would make great first languages.
EDIT:
list of beginner programming assignments appeared overnight might be just what you are looking for.
It really depends on your brother's learning style. Many people learn faster by getting their hands dirty & just getting into it, crystallising the concepts and the big picture as they progress and build their knowledge.
Me, I prefer to start with the big picture and drill down into the nitty-gritty. The first thing I wanted to know was how it all fits together then all that Object-oriented gobbledygook, then about classes & instances and so-on. I like to know the underlying concepts and a bit of theory before I learn the syntax. I had a bit of an advantage because I wrote some games in BASIC 20 years ago but nothing much since.
Perhaps it is useful to shadow a production process by starting with an overall mission statement, then a plan and/or flowchart, then elaborate into some pseudo code (leaning towards the syntax you will ultimately use) before actually writing the code.
The golden rule here is to suss out your student's leaning style.
If your brother has access to iTunes, he can download video lectures of an introductory computer science course given by Richard Buckland at the University of New South Wales. He's an engaging instructor and covers fundamentals of computing and the C language. If nothing else, tell your brother to play the vids in the background and some concepts might sink in through osmosis. :)
COMP1917 Higher Computing - 2008 Session 1
http://deimos3.apple.com/WebObjects/Core.woa/Browse/unsw.edu.au.1504975442.01504975444
If the link doesn't work, here's a path:
Home -> iTunes U --> Engineering --> COMP1917 Higher Computing - 2008 Session 1
there's a wikibook that is pretty good for learning python.
I don't know how the wikibooks are for other languages, but I personally learned python from the wikibook as it was in Feb 2007
ps - if you're unfamiliar with wikibooks, it's basically the wikipedia version of book authoring. it's sort of hard to describe, but if you check out a few of the books on there you'll see how it works
Python Programming for the absolute beginner
Python Programming for the absolute beginner cover http://safari.oreilly.com/images/1592000738/1592000738_xs.jpg
I think Python is a great idea. I would give him a few basic assignments to do on his own and tell him that any dead ends he hits can probably be resolved by a trip to google. For me, at least, solving a problem on my own always made it stick better than someone telling me the solution.
Some possible projects (in no particular order):
Coin flip simulator. Let the user input a desired number of trials for the coin flipping. Execute it and display the results along with the percentage for heads or tails.
Make a temperature converter with a menu that takes user input to choose which kind of conversion the user wants to do. After choosing the conversion and doing it, it should return to the main menu.
Here's an example of an extended converter with the same idea: http://pastebin.org/6541
Make a program that takes a numeric input and displays the letter grade it would translate to. It'll end up evaluating the input against if and elif statements to find where it fits.
Make a simple quiz that goes through several multiple choice or fill in the blank questions. At the end it will display how the user did. He can pick any questions he wants.
Take an input of some (presumably large) number of pennies and convert it into bigger denominations. For example, 149 pennies = 1 dollar, 1 quarter, 2 dimes, and 4 pennies.
Create a simple list manager. Be able to add/delete lists and add/delete entries in those lists. Here's an example of a christmas list manager: http://pastebin.org/6543
Create a program that will build and then test whether entered numbers form a magic square (with a 2D array). Here's some sample code, but it should really print out the square at each step in order to show where the user is in terms of buliding the square: http://pastebin.org/6544
I would also suggest doing some stuff with xTurtle or another graphics module to mix things up and keep him from getting boring. Of course, this is very much practice programming and not the scripting that a lot of people would really be using python for, but the examples I gave are pretty much directly taken from when I was learning via python and it worked out great for me. Good luck!
Just make it fun !
Amazingly Scala might be the easiest if you try Kojo
If your brother likes puzzles, I would recommend Python Challenge. I wouldn't use it as a formal teaching tool in a 1 on 1 tutorial, but it's something he can do when you're not together to challenge himself and have some fun.
Python Challenge
After going through a few free e-books, I found the best book for learning to program was Head First Programming published by O'Reily Press. It uses Python as the language and gives you programs to work on from the very start. They are all more interesting that 'Hello World'.
It's well worth the money I spent on it, and since it's been out for a bit you may be able to find a cheaper used copy on Ebay or Amazon.
If you want to teach the basics of programming, without being language specific, there is an application called Scratch that was created in MIT. It's designed to help people develop programming skills. As users create Scratch projects, they learn to create conditions, loops, etc. There is a also a community of scratch projects, form which projects can be downloaded - that way you can explore other people's programs and see how they were built.
I think that once he has the basics (variables, loops, etc) down you should try to help him find something specific that he is interested in and help him learn the necessities to make it happen. I know that I am much more inclined and motivated to do something if it's of interest to me. Also, make sure to let him struggle though some of the tougher problems, nothing is more satisfying than the moment you figure it out on your own.
I was taught by learning how to solve problems in a language agnostic way using flowcharts and PDL (Program Design Language). After a couple weeks of that, I learned to convert the PDL I had written to a language. I am glad I learned that way because I have spent the majority of my years programming, solving problems without being tied to a language. What language I use has always been an implementation detail and not part of the design.
Having to solve the problem by breaking it down into it's basic steps is a key skill. I think it is one of the things that separates those that can program from those that can't.
As far as how you tackle the order of concepts of a language I believe the easiest way is to decide that is to have a project in mind and tackle the concepts as they are needed. This lets you apply them as they are needed on something that you are interested in doing. When learning a language it is good to have several simple projects in mind and a few with progressive complexity. Deciding on those will help you map out the concepts that are needed and their order.
I would recommend also watching some screencasts - they are generally created in context of a specific technology not a language, though if there's Python code displayed, that'll do :). The point is - they're created by some good programmers and watching how good programmers program is a good thing. You and your brother could do some peer programming as well, that might be an even better idea. Just don't forget to explain WHY you do something this way and not that way.
I think the best way to learn programming is from good examples and try not to even see the bad ones.
Robert Read wrote a useful guide, How to be a Programmer, which covers a wide area of programming issues that a beginner would find helpful.