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My name is Ashish Mahabal, and we'll
be continuing with the module on best

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programming practices,
the last part of it.

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So today we'll be seeing a little
bit about portfolio building.

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But before that,
just a quick word about metaprogramming.

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So what that means is that,

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you want, you will want to separate
some configuration files, which have

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specific data which can be changed by
either the user or you, yourself will be

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changing that later that allows you to
have all the abstraction in your code.

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And then that can be separated, which
doesn't have to be touched again, and

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again, or perhaps even ever
once you have the metadata, or

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the bits that need to be changed
in separate configuration files.

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So you should have those configuration
files for various things that those can be

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plain text files, and
you can change that very easily, later on.

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[COUGH] When it comes to
portfolio building, what I

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would like to advise is that you should
have as wide a repertory as possible.

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So you should have mastery of say,
one or two languages.

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But also have many general
tools at the tip of your hands.

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You should especially learn
how to handle plain text.

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Many people, I've found, just don't know
how, when they're sent a plain text file,

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what to do with that.

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You should remember that it's easier to
test, you can have config files in that or

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the other thing that you should
remember is you would normally be

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accessing shells on your computer like
especially if you're Unix like computers.

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Learn how to handle those and
there are very powerful programs that

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the shells come with like find and
said and arc and create.

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Make sure that you know
them at least to an extent,

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because rather than writing
some long programs,

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you'll be able to adjust those
programs to do a lot of work for you.

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Similarly, if you are using a batch, or

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CSAs, then there are some batch
RC DCHRs like files that go with them.

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Learn about the details of those, and

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you'll be able to accomplish a lot by
knowing the intricacies of such things.

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And it's not a big learning curve,
it's fairly straight forward to learn.

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Just the very fact that they exist is not
known to many people, but once they get

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into it they realize how quickly they
can do a lot of things with those.

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Similarly with languages,
try to learn some languages that have

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completely different flavors,
some that you need to compile,

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some where spacing is important,
some in which spacing is not important.

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Because all of them have their strings and
then once you know some different types

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then you'll be able to use them in
different situations more efficiently.

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Again with editors, I'm sure that each
of you have some favorite editor and

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it's good to know that
as much as possible.

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But make sure that you know a couple
others at least to an extent.

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If you are very good eMax, try to learn
VI or Sublime or something like Nano.

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And you'll find that sometimes you'll
find using the editor quickly for

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something short is very useful or when
someone else is describing something to

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you in their favorite editor,
you'll be able to get that quite well.

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So each of these editors comes
with various interesting tools

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which are time-saving, like syntax
highlighting is possible these days,

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auto completion, auto indentation,
and various Boilerplates, and

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of course there is built in help.

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So, try to make sure you
understand of those.

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And, like was mentioned before,
you have cheat-sheets, even for editors.

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So make sure that you have those printed
out and put next to your work space so

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that you can take a look at
them whenever you want to.

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Then if you are trying to do some text
manipulation, language like Bowline,

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Ruby, are extremely
powerful in doing that so

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learned just a little bit
of those two languages.

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And there can be various code generators
that will help along in a big way.

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So small subroutines that can go with
this code generator can write most of

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your code quite easily.

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These also include shell scripts that can
be fairly easily written or config files.

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We talked about those
a little bit earlier.

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In our transient astronomy we
have something called we have

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built something called Skyalert.

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And when a new transient is found,
a transient is an object that changes in

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brightness and
we are interested in studying those.

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When a new transient is found
the Skyalert auto code generator,

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the active code generator goes out and
fetches data from various archives.

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And then, it incorporates those
data into the data that we

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farmed from the transient.

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And then, if certain conditions are made,
then it can do additional things like

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running some other programs or
raising an alert, et cetera.

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So, it becomes very handy, being able
to write such, active code generators.

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And it's not difficult,

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so that's definitely something that you
should try to make part of your portfolio.

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Then there are various
websites that you can visit,

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like the 99 bottles of beer website.

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It shows how to write that particular
program in various different programming

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languages and that allows you to
compare how those languages work and

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similarly there
are programming shoot outs.

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You can compare different
languages there that

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are of course various debates that go on.

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But here is a more objective look at
various features of different languages.

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Similarly Project Euler
is a fantastic resource.

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There, there is mathematically
problems of state aid and

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you're suppose to use programs to
solve them and once you solve them

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you get access to of the same program
written in other programming languages.

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They simply, in the site was hacked and
for some time that may not be available,

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but I'm sure that'll be coming back soon,
and it's a fantastic resource.

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You already saw earlier
about memorization.

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Definitely that's something
you should learn about,

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radius, caching digits, et cetera.

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I won't go into more
details of that right now.

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I'm going to leave you a bit,
a couple of exercises.

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It is an exercise.

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If you are given a certain amount and if
you want to find out how many ways there

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are of dividing that amount using say
the standard US coins pennies, nickels,

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dimes and quarters, that is coins of
denomination one, five, ten and 25.

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How can you do that?

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The problem is normally stated where you
want to divide 100 cents into 1s and

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5s and 10s and 25s.

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If you start with simply a one, if you are
separating a single penny into these four

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denominations, there'll be
only one way of doing that.

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Two, three, four, again,
there'll be one way of doing that.

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But the moment you come to five,
you can either get one coin of five, or

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five coins of one.

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So there are 2 ways.

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And then, as you go to higher numbers,
there'll be multiple ways of doing that.

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So the next part of the question, and this
is where you'll be able to build your,

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program is, you should answer this
question for all numbers from one to 100.

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And then, having answered that,
you should find out the ones that,

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which have, which return and odd number of
different number of ways of doing the sum.

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And then, you should simply
say whether the odd number of

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numbers that odd or even.

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So that's essentially an exercise so

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you should definitely try to take a,
give it a go.

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Here is another exercise.

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On lifehacker.com sometime
back a program was put

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out about a better strategy for hang man.

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Given a particular length of word
that you are looking for and

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given frequencies of letters
in different words how one

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can solve that in a meaningful and
easy fashion.

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I'd like you to try to solve the same
thing using only Unix commands.

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I mentioned a few earlier so
try to take a look at that.

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But that will stop back summarizing
one of the lessons that we

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may have learned from this
best programming practices.

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You should remember that a chain
is as weak as its weakest link so

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try to have your portfolio include
many strong of languages, and

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find the strong features of each of them.

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include a lot of comments wherever
possible, for yourself and for others.

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Make sure that you write lots and lots of
tests, that your programs are orthogonal.

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Don't duplicate yourself,
design by contract, and

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again, know the features of the language
of whatever module that you are using.

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In debugging, try to optimize your
programs in the way that we have told you

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about, not in arbitrary ways.

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Follow the best practices and
have fun coding.

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Thank you