Mono, Tomboy, .NET and my mistake

My Mother told me something a long time ago, if you are wrong and you made a mistake this is not something to be ashamed of as long as you admit you did.

So maybe it is time to admit it for some parts. I am talking about my post on Mono/TomBoy and how it tangles in .NET into mainstream Linux. After posting this blogpost it took some time for Google to pick it up and tell people the page was out in the open. However after it did I was contacted via a comment by the lead developer from the Tomboy project.

Sandy had to state some things about my post and I am glad to have received this update. It might changes my opinion on some parts however not in all. Sandy stated the following:

1) Mono does not depend on any .NET or any Microsoft code. It is a free software *reimplementation* of the .NET runtime, framework, and languages. All of the code you need to run Tomboy (for example) is 100% open source and free software, and totally compatible with the GNU GPL. Richard Stallman agrees with this and has stated it before. So you are more than welcome to download the Mono source, and tweak the runtime or change the C# language or do anything you want! :-)

Agreed, you are completely right and I was wrongly informed that some parts of Mono where closed. I did already know that the complete sourcecode of Tomboy was opensource and could be changed however I was under the impression that some parts of Mono where still closed and under control by Microsoft. So I have to change my opinion on this based upon the information from Sandy.


2) Richard Stallman's main complaints about Mono that I have heard are the following:
a) Because Mono is a reimplementation of .NET, and Microsoft decides what is in .NET, you could say that Microsoft indirectly influences what ends up happening in Mono.
b) Microsoft has a lot of patents on a lot of things, and Stallman is concerned that there might be patents that affect Mono.

So, Stallman's argument against Mono is not about having the source, or it not being free software, or anything like that. It's more of a political and philosophical thing.

Lets not keep us at the statement given by Stallman. My own opinion is that as a patent might (read might) be end up in mono it can influence Tomboy so one should not take this risk. Maybe I am a purist like Stallman that might be the case. However this is my opinion. So as I stated in my previous post I would like to be able to pack my stuff and go to a island and be able to do whatever I like. So even if I have all the sourcecode I can still end up in a situation where a ship comes to my island and tells me I am doing illegal things because I am tinkering with patents by Microsoft. To prevent this one should pick a language in which this will never happen.

It might be a political and philosophical discussion however I think we have to have this discussion to be able to think about what we do allow in mainstream Linux and what not. Currently I am under the impression that we should prevent this wherever we can to protect the purity of Linux. In my humble opinion we should try to prevent it from happing that anything which potentially can harm the free form of linux ends up in a Linux distribution.

So I might have made some mistakes and I hope I have corrected them in this post, I might have been not to clear on some points and I hope I have corrected them in this post and I hope some people would like to comment on this post so we might be able to start a discussion on it. This is because I have the feeling this is a discussion we will have to have to decide what to do with those political and philosophical implications of opensource.

No .NET in Linux

Richard Stallman has opposed against a single app, Tomboy, which has become part of the current unstable release of Debian Linux. Reason for this is that it is depending on MONO. Mono is a cross platform, open source .NET development framework and his concern is that Microsoft might someday stop with .NET and as MONO is depending on .NET also all the applications build with MONO are depending on it and so are depending on a Microsoft. His statement is that all that is in Linux should be open and by this all the source codes should be available which is not the case with .NET.

Richard is seen as one of the most brilliant people in the opensource world however also seen as one the hardliners in the opensource world who is not willing to make any compromise on his thoughts of what opensource is and should be. Some people think he is reacting to strong and state that he has become to much of a hardliner. I do however agree with him on this. Linux should be complete opensource and by adding a application like Tomboy we are compromising to this thought. Linux should be a platform that you can change to your liking and by having a dependancy to closed source you loose this ability.

In my opinion you should be able to pack linux on a laptop, get all the sourcecode, and move to a deserted island and be able to do anything you like to it without having the need to contact anyone. Complete freedom and not depending on any other person. By adding tomboy to it you are depending on Microsoft and to the thinking of Microsoft. If you need a function changed in .NET for some reason you will have to wait until Microsoft decides to do it, if they ever do it. And not only is this the case with .NET it is also the case with for example C#.

it is not a issue of opposing against a language, everyone should pick the language he or she likes to use. It is opposing against mixing licenses in Linux. As Mono is depending on .NET and .NET is not GNU/GPL compliant it should never become part of a linux mainstream release. If you really like it you should have the option to implement it however I would vote against it as it is not GNU/GPL compliant.

If you coding in for example Python and you need a special part of the compiler changed for some reason you do have the ability to go to the Python website, check the sourcecode, change it and make you own version. That is complete freedom as it should be. Not many people will do it however you do have the option if it is really needed. As some person from the US army once stated about systems that would make it to the battlefield, “if we can not hack it we do not pack it” and that is a very true statement. If you do not have the option to make modifications to it when the situation calls for it it is useless.

So, placing Tomboy in Debian and by this making yourself depending on Microsoft is a very bad move. Richard can be seen as a hardliner however I can only agree with him on this part.

Linux find command

sometimes finding out the way a Linux or UNIX command is working can be fun. For example I have been looking into the way how the find command is working and I have had a lot of fun with it. find can give you a great option to locate exactly the files you want and with the pipe options in Linux you can get exact that output you want and need.

The reason for me to look into the find command was a interface at a server at a customer. The interface consist basically out of remote servers who place files with FTP in certain locations. On the server side we have a couple of processes scheduled looking for files in certain directories who will process and delete the files. The processes run every 10 minutes, as we have some files that can be large the processing can take some time so files can be at the location for some time. However, never longer than 1 hour. So what we want the administrators would like to have is a system that looks for files older than 1 hour because this can indicate a interface that is stuck for some reason.

As we maintain a large number of servers and interfaces this can not be done by hand and has to be automated. The solution is to schedule a scrip that will look for the files and send the output every hour via mail. Even in the cases no files older than 1 hour are find a mail should be send because this is a trigger to see if the check has run.

First is to find out how you can locate files older than 1 hour. We will be using the find command for this. We will use the following command:

find . -type f -mmin +60

find is the command to find files. the “.” indicates that you want to look in the current directory. than we have the “-type f” option. “-type” allows you to set what kind of files you are looking for. f states that you are looking for regular files. If you for example are looking for directories you can state d and if you are looking for a link you can state l. for the complete list you can refer to the man page of find.

We also states -mmin +60. This indicates that you are looking for files older than 60 minutes. You can play with +60, if you are looking for files for example that are NOT older than 60 minutes you can state -60 instead.

Now we do not want the standard output because we do want to have more information, somewhat like the output we get from the ls command. For this we can do a “internal” pipe to the ls command with the -exec option. for the -exec we set ls -la so we get all the ls output. The command will look like this:

find . -type f -mmin +60 -exec ls -la {} \;

However this is still not what we want because we only want the filename and the time it is created. currently we get something like:

-rw-r–r– 1 jlouwers staff 0 Oct 11 11:14 ./x
-rw-r–r– 1 jlouwers staff 0 Oct 11 11:23 ./z/x

So we have to change the output and we can do this by using awk. We have to pipe the output from the above command to awk and than make sure we only get what we want. And what we want is filename and time. nothing more. So we can do this by using awk. According to the UNIX manual pages AWK is a pattern scanning and processing language… simple told.. it is a damn handy tool to make stuff look like the way you want it.

We pipe the data into the following command:
awk ‘{print $8,$9,$10}’

which makes the complete command look like:
find . -type f -mmin +60 -exec ls -la {} \; | awk ‘{print $9,$10}’

and the output will look like:
11:14 ./inbound_225/225int_inb.txt_65466
11:15 ./inbound_225/225int_inb.txt_65467
11:25 ./inbound_225/225int_inb.txt_65468
11:23 ./inbound_256/256int_inb.txt_43221
11:24 ./inbound_256/256int_inb.txt_43222

One last thing you might want to add, if you are running the command on a directory and you do not have access to all sub-directories you might end up in a situation where you get access denied errors in your output which can disturb your checks so you can pipe all the error messages to /dev/null . You can do this by editing the command that it will look like the command below:

find . -type f -mmin +60 -exec ls -la 2>>/dev/null {} \; | awk ‘{print $8,$9,$10}’

A lot more options are in the find command, you have however to check out the manual and have some fun with it while trying.

Sun Solaris manual pages

We are now providing again a option to check UNIX manual pages from our website. Special thanks to the University of Alabama, University of Athens, SGI and the University of Southampton.

Read the complete story at terminalcult.org >>

TEDx in Amsterdam

TEDx is coming to Amsterdam. Very exciting to have a TEDx event in Amsterdam. TED is a small nonprofit devoted to Ideas Worth Spreading. It started out (in 1984) as a conference bringing together people from three worlds: Technology, Entertainment, Design.

Read the complete story on terminalcult.org >>

Blackberry and Twitter

For a long time RIM, the company behind blackberry, hold back on developing a twitter app. They found that companies like ubertwitter, twitterberry, and such could do the job. And they did the job quite nice however now RIM would like to jump the twitter bandwagon.

Crackberry.com is running a blogpost that RIM will launch a official twitter app. Nice.....

Python database abstraction

Even do I am going cover to cover (when I feel like it) in a Python book I sometimes likes to make a exception. This is one of those exceptions. I already have covered ADOdb in a previous blogpost. As you might recall I wrote a piece on on ADOdb in combination with PHP.

However I discovered that ADOdb is also available for Python. Now you have the option to write ADOdb statements and this abstraction layer will create the correct syntax when you deploy it on your database. Meaning that if you ever switch from a MS-sql database to a Oracle database you will not have to revise all your code. Simply tell the abstraction layer that it now should talk Oracle SQL instead of MS SQL and you are in business.

Starbucks Iphone

Starbucks is launching a new app for the iPhone. It will be launched on the US version of AppStore first. As we all know strabucks is already a very internet friendly company and me included a lot of people have spend some time with a laptop in a Starbucks to get some work done.

Now Starbucks has launched which can help you enjoy it even more. It can help you locate a starbucks close to you so you will never spend to much time looking for a place to get coffee. You can also give credit points to coffee and in this was indicate what your favorite is. This will help starbucks to do some marketing I guess…..

A second part of the application can be used only in a couple of test starbucks in the US. You can place a amount on your iPhone app and use it to pay for your coffee. It works in the same way as yur starbucks card would do. Only difference is that it is now on your iPhone.

I am really wondering how this will fly. If this is a success and I guess it will be we will see a lot of those applications coming in the upcoming time for other companies. Gas stations for example can come to mind. So you phone will become more and more your wallet. Eventually someone will start to build a new app which is capable of holding all the custom apps. Years ago people where already talking about pay with your phone. Well I guess this is one of the best steps towards that goal. Some pilots and options with SMS pay are already tried and on the run at the moment however I feel personally that this is he first attempt in a way that it can be accepted by the public.

However, security comes to mind. I would love to dive into this to find out what the security is on this thing.

Nomee ..... NO!

Just been reading a item about Nomee on mashable.com by christina warren, nomee is a new tool where you can monitor and follow people on all kind of different social networks and channels.

A great app, and something that can help you, however,.... why a app? It is a application I have to download and install on my computer. I can not download it on my phone and why is it not just a web application.

Nomee, it looks great, it looks like fun however for me it is not a usable thing at this moment. Why not, I am on the move most of the time I have time to follow people, read stuff and such. So it has to be mobile. More mobile than Nomee is at the moment. A mashup for social networks is great however not in the form as Nomee envisions.

IndentationError: expected an indented block

IndentationError: expected an indented block

Indentation is a big part of writing Python code, and it is a good thing in my opinion because it makes you write better and cleaner code. indentation is used to place code more to the right. so instead of writing your code like below;

#!/usr/bin/python
n = 1
i = 1
print "start code"
while n<=10:
i = 1
print "start the table of", n
while i<=10:
print i,"x 8 =", i*8
i=i+1
n=n+1
print "end code"

you have to write your code using indentations to make it work in python. Meaning a functioning code will look like this;

#!/usr/bin/python
n = 1
i = 1
print "start code"
while n<=10:
  i = 1
  print "start the table of", n
  while i<=10:
    print i,"x 8 =", i*8
    i=i+1
  n=n+1
print "end code"

As you can see it will make your code more readable because you can see what is inside a while look and what not. This is directly the reason why it is used in Python coding, not to make your code look nice, it has a functional part to it. In some languages you indicate the begin and end of a codeblock like a while loop with brackets, a { to start and a } to end the while block. In python you use indentations. If you do not make sure your indentation is correct you will most likely end with a " IndentationError: expected an indented block" error. Lucky for you a line number will be given so you can debug your code quickly.

Personaly I think that the use of indentation for codeblocks is great. It will learn you to write your code in a way that it is more readable for other developers. That is at least on this part. I remember re-writing code from other developers and first making sure all the indentation is correct so it becomes more readable, in in python that is no longer needed because if you have your indentation not set correct in your code you will not be able to run it in the first place. Meaning that, if your process is correct, no developer can commit code into production if the indentation is incorrect. That is to say, for the parts where it is needed.

Final word, indentation in Python code,….. a good thing.

Python while loop

As I will go cover to cover in a book about Python coding I will have to touch the loop section. A loop is in basics a repeating command until a criteria is matched. You will see loops in almost every language.

This is what Wikipedia has to say on it:
In most computer programming languages, a do while loop, sometimes just called a do loop, is a control flow statement that allows code to be executed repeatedly based on a given Boolean condition. Note though that unlike most languages, Fortran's do loop is actually analogous to the for loop.

The do while construct consists of a block of code and a condition. First, the code within the block is executed, and then the condition is evaluated. If the condition is true the code within the block is executed again. This repeats until the condition becomes false. Because do while loops check the condition after the block is executed, the control structure is often also known as a post-test loop. Contrast with the while loop, which tests the condition before the code within the block is executed.

It is possible, and in some cases desirable, for the condition to always evaluate to true, creating an infinite loop. When such a loop is created intentionally, there is usually another control structure (such as a break statement) that allows termination of the loop.

Some languages may use a different naming convention for this type of loop. For example, the Pascal language has a "repeat until" loop, which continues to run until the control expression is true (and then terminates) — whereas a "do-while" loop runs while the control expression is true (and terminates once the expression becomes false).




As can be seen below you can also nest a loop inside a loop:

#!/usr/bin/python
n = 1
i = 1
print "start code"
while n<=10:
  i = 1
  print "start the table of", n
  while i<=10:
    print i,"x 8 =", i*8
    i=i+1
  n=n+1
print "end code"

ORABPEL-05002

Recently I encounter a project where they used Oracle BPEL on a Oracle Application server 10G. It turned out that some of the BPEL processes suddenly stopped when waiting for a asynchronous callback method in BPEL.

After some searching I finally found a usable error message in one of the error logs. You can see it at the end of this blogpost. It turned out that this could be solved by changing some settings in XML configurtaion files. We found that by changing the transaction-timeout settings the problem is solved.

If you ever encounter a error like below you might want to check the "Setting Properties for BPEL Processes to Successfully Complete and Catch Exception Errors" section in this Oracle manual.

You will have to change some settings in $SOA_Oracle_Home\j2ee\home\config\transaction-manager.xml and in $SOA_Oracle_Home\j2ee\home\application-deployments\orabpel\ejb_ob_engine\orion-ejb-jar.xml . After this rememeber to stop and start to have the new settings activated.

<2009-09-03 14:05:07,617>    failed to handle message
javax.ejb.EJBException: An exception occurred during transaction completion: ; nested exception is: javax.transaction.RollbackException: Timed out
javax.transaction.RollbackException: Timed out
--
        at com.collaxa.cube.engine.dispatch.BaseScheduledWorker.process(BaseScheduledWorker.java:70)
        at com.collaxa.cube.engine.ejb.impl.WorkerBean.onMessage(WorkerBean.java:86)
        at sun.reflect.GeneratedMethodAccessor42.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:585)
        at com.evermind.server.ejb.interceptor.joinpoint.EJBJoinPointImpl.invoke(EJBJoinPointImpl.java:35)
        at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:119)
        at com.evermind.server.ejb.interceptor.system.DMSInterceptor.invoke(DMSInterceptor.java:52)
        at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:119)
        at com.evermind.server.ejb.interceptor.system.SetContextActionInterceptor.invoke(SetContextActionInterceptor.java:44)
        at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:119)
        at com.evermind.server.ejb.InvocationContextPool.invoke(InvocationContextPool.java:55)
        at oracle.j2ee.connector.messageinflow.MessageEndpointImpl.OC4J_invokeMethod(MessageEndpointImpl.java:297)
        at WorkerBean_EndPointProxy_4bin6i8.onMessage(Unknown Source)
        at oracle.j2ee.ra.jms.generic.WorkConsumer.run(WorkConsumer.java:266)
        at oracle.j2ee.connector.work.WorkWrapper.runTargetWork(WorkWrapper.java:242)
        at oracle.j2ee.connector.work.WorkWrapper.doWork(WorkWrapper.java:215)
        at oracle.j2ee.connector.work.WorkWrapper.run(WorkWrapper.java:190)
        at EDU.oswego.cs.dl.util.concurrent.PooledExecutor$Worker.run(PooledExecutor.java:814)
        at java.lang.Thread.run(Thread.java:595)
javax.ejb.EJBException: An exception occurred during transaction completion: ; nested exception is: javax.transaction.RollbackException: Timed out
--
        at com.collaxa.cube.engine.dispatch.BaseScheduledWorker.process(BaseScheduledWorker.java:70)
        at com.collaxa.cube.engine.ejb.impl.WorkerBean.onMessage(WorkerBean.java:86)
        at sun.reflect.GeneratedMethodAccessor42.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:585)
        at com.evermind.server.ejb.interceptor.joinpoint.EJBJoinPointImpl.invoke(EJBJoinPointImpl.java:35)
        at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:119)
        at com.evermind.server.ejb.interceptor.system.DMSInterceptor.invoke(DMSInterceptor.java:52)
        at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:119)
        at com.evermind.server.ejb.interceptor.system.SetContextActionInterceptor.invoke(SetContextActionInterceptor.java:44)
        at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:119)
        at com.evermind.server.ejb.InvocationContextPool.invoke(InvocationContextPool.java:55)
        at oracle.j2ee.connector.messageinflow.MessageEndpointImpl.OC4J_invokeMethod(MessageEndpointImpl.java:297)
        at WorkerBean_EndPointProxy_4bin6i8.onMessage(Unknown Source)
        at oracle.j2ee.ra.jms.generic.WorkConsumer.run(WorkConsumer.java:266)
        at oracle.j2ee.connector.work.WorkWrapper.runTargetWork(WorkWrapper.java:242)
        at oracle.j2ee.connector.work.WorkWrapper.doWork(WorkWrapper.java:215)
        at oracle.j2ee.connector.work.WorkWrapper.run(WorkWrapper.java:190)
        at EDU.oswego.cs.dl.util.concurrent.PooledExecutor$Worker.run(PooledExecutor.java:814)
        at java.lang.Thread.run(Thread.java:595)
Caused by: javax.transaction.RollbackException: Timed out
        at com.evermind.server.ApplicationServerTransaction.checkForRollbackOnlyWhileInCommit(ApplicationServerTransaction.java:633)
        at com.evermind.server.ApplicationServerTransaction.doCommit(ApplicationServerTransaction.java:273)
        at com.evermind.server.ApplicationServerTransaction.commit(ApplicationServerTransaction.java:162)
        at com.evermind.server.ApplicationServerTransactionManager.commit(ApplicationServerTransactionManager.java:472)
        at com.evermind.server.ejb.EJBTransactionManager.end(EJBTransactionManager.java:132)
        ... 29 more
<2009-09-03 14:05:07,618>    Failed to handle dispatch message ... exception ORABPEL-05002

Message handle error.
An exception occurred while attempting to process the message "com.collaxa.cube.engine.dispatch.message.instance.PerformMessage"; the exception is: An exception occurred during transaction completion: ; nested exception is: javax.transaction.RollbackException: Timed out

ORABPEL-05002

Message handle error.
An exception occurred while attempting to process the message "com.collaxa.cube.engine.dispatch.message.instance.PerformMessage"; the exception is: An exception occurred during transaction completion: ; nested exception is: javax.transaction.RollbackException: Timed out

Twestival in Amsterdam

Looking for a party, hoping to meet all the people you know from twitter? Go and have fun at Twestival. Twestival is a festival which is organized and promoted using twitter. Between 10 and 13 September you will be able to find Twestival’s all over the world.

Twestival is not only about having fun, it is also about helping. The way it is done is you have to pay a small amount when you want to join a party and by this you give the money to a charity of your choice. For example in Amsterdam a party will be held in Odeon which is promoted and organized by @AncillaTilia.

So if you are looking for a great party, like to meet your twitter friends and help a good cause… go and find a local Twestival event and have a great party.

Clean desk policy

Started the new clean desk policy at home again for my own working area. Every now and then, specially on a rainy sunday, I get the idea that a clean desk is perfect for me. Today is such a sunday and I started cleaning my desk again. Somehow I do get a lot of paper mail from all kind of vendors and I do collect books and magazines arround my working area.

Most of it contains some interesting information and I would like to post some of those things here before dumping the magazines and such into a dumpster (that is a paper recycle dumpster).


efresh.com
Just found a item on efresh.com and a interview with director Hans Robben. efresh.com is the ebay.com for fresh food. Ever in need to buy a shipload of shellfish, you can check efresh.com and bid on it. This is where you as a farmer, fisherman or company can place your goods and people can start placing bids. The magazine where I found it is not that old and so is efresh.com. I am wondering to see how this open marketplace will hold. The idea is great and i hope to see more initiatives like this.

Cool looking workplaces.
I recently changed my workspace to a new office. it is very modern and very nice looking. A real nice and cool working environment with a lot of open spaces. It really gives me a vibe in a good way. However I am still wondering how it is to work a for example at Google. Google is still on my list of companies I want to work for one day. That can be as a employee or as a hired consultant. Anyway I want to work at google maybe one day. Why, have a look at the one of the offices on this website. However, talking about a nice working environment. I think that the office of Wieden+Kennedy in Amsterdam is a really really nice place to work. The way the design of the office is done is great. You can find more information at this website including some pictures nextarchitects.com.

Space Barley
Most likely you never have heard from it and most likely you have never tasted it. Space barley is a beer that is made of barley grown in the ISS space station. Scientists have tested what grows in space so that when we try to colonize space one day we know what to grow. Barley can be used for this and one of the great things is you can make beer from barley. Well it was a test and most likely it will never become a mass product so if you had the pleasure of drinking a bottle of it.... to bad for you!!! you should have kept it and sold it in 10 years and made a fortune of it.

Building a house?
Thinking about building a house? Well have a look at the solardecathlon.org website. You can find a lot of great pointers on how to make your house green and energy efficient. And building something green is something hippy like? Forget it, green is cool and it gives you a great extra benefit in the costs when living in your house when it is done.

Python if elif else

In almost every programming language you have some basic commands and functions, basic construction options so to call. "if" is one of those, "the if statement is used to check a condition and if the condition is true, we run a block of statements (called the if-block), else we process another block of statements (called the else-block). The else clause is optional." So we can have a check and if this check is returning a true we can take some action. Lets see in a very basic example how this works, I will show this with a very small python script.

#-----------------------
#!/usr/bin/python

#set some variables
var0 = 2
var1 = 1

if var0 > var1:
print "var0 IS larger than var1"
elif var0 < var1:
print 'var0 IS smaller than var1'
else:
print 'var0 is not larger or smaller than var1, maybe they are the same?'

print 'and we have left the if elif else'
#-----------------------

Sow with this very simple script we can show what action is taken, or what text is printed to the console. You can test this by playing with the values of var0 and var1 and see for yourself what the result is. Basically I do not want to spend to much time on the "if" part as this should be a very basic part of programmers knowledge. The only part that can be tricky is that in some languages elif is written as "els if" or "elsif" or even "if else". In Python it is if, elif and else. Just something you have to know when you start with Python.

So as you can see making decisions with if statements is a very basic way of making decisions. Another thing which is good to know is that you can nest if statements. So if you come into if-block you can create inside this block another if-block to make your decision even more precise. In the script below I first determine if var0 and var1 are equal. If this is not the case we "open" a new if-block to see what is exactly the case. Is var0 larger or smaller than var1. Just play arround with the values of var0 and var1 and you will see what it can do.

#-----------------------
#!/usr/bin/python

#set some variables
var0 = 2
var1 = 2

print 'starting some nesting'

if var0 != var1:
print 'var0 is not the same as var1'
if var0 > var1:
print 'var0 is larger than var1'
elif var0 < var1:
print 'var0 is smaller than var1'
elif var0 == var1:
print 'var0 is the same as var1'

print 'done with the nesting'
#-----------------------

Also something that you might know from other languages is that the content of if-block should be within brackets and that it is constructed something like below:

#-----------------------
if(condition){
action
}
else if (condition II){
action
}
else{
action
}
#-----------------------

In Python this is not used, you might like it or you might not like it that this is not in place however the people who developed the Python language did not see the need of it. I personally think it is a missing part, this is simply because I am within the group of bracket lovers who like to have it nice and tidy inside a couple of brackets. If you are in the same group.... you will get used to it finally.. I did also. Upside, you will never have to count opening and closing brackets again... remember those long nights of debugging a bracket problem?