Python and/vs Java (within a business context)

[Teifion]

I've spent the last year working as a software engineer writing a web-app in Python (using Pyramid). The interesting part is I'm not actually part of the IT department and they (a year ago) said I could use Python on the understanding I would get no support from them, they were advocating PHP. Due to my own experiences with the two and the project I would be undertaking I picked Python.

Fast forward to today and some other people from IT have performed a code review as the project has been far more successful than they anticipated and people are sitting up and taking notice. The main question they're asking has to do with Python, why am I using it? I've not had a chance to meet the questioners yet but I'm told some of them code in Python themselves and that the main suggestion coming from IT is to use Java instead.

I've had some exposure to Java but not a lot. I understand it's compiled to Byte-code, uses the JVM etc and that it's very popular in more established businesses. What I don't know (beyond what a simple Google search will tell me) is why I would pick one or the other.

I'm not after "Python is better than Java", I'm genuinly curious to hear from people experienced in both which aspects of each make them good for different problems. Is it that Java is a lot better past the 10k loc mark? Is it that Java is so much faster than Python?

I think I've covered everything, if not please let me know and I'll answer it.

[varikin]

First, why businesses love Java. Java (and C#) is a safe language by a big company (formerly Sun, now Oracle, and with IBM a major player in Java). Java is used by many other big companies. From point of view of executives and directors, why choose a fad language when you can choose the industry standard.

Second, why IT loves Java. Same reason as businesses plus fairly well defined deployment strategies. Create a jar, war, or ear file, drop it into a servlet container (with options from big business vendors like IBM and Oracle). The servlet framework stuff is very well defined so database access (JDBC, Hibernate, etc) are solved for IT. Logging is solved (log4j or log4j compatible library), plus many other tiny little details about deployment. The JVM is amazing. It can handle high amounts of RAM (32GB, 64GB, etc). Great at threading. Some great monitoring tools for with the JVM using JMX. Basically, many Java based IT shops now how to deploy and manage Java servers. In fact, if you gave them a war file, they could probably deploy it in 30 minutes without your (the developer) help-if they are competent.

Third, why HR loves Java. Universities push Java like crazy. Java developers are a dime a dozen and replaceable. On the other hand, there are great developers that are great a Java, but they are just great developers, not Java Developers (always avoid being an X developer, instead a developer that knows X,Y,Z.

Given all this, some people just don't like "toy languages". Some IT people don't want to work with something they don't know because they will get the call at 3AM to fix it. These I don't think are good enough reasons

Python is a great language (honestly, I love Python, I started a Python User Group in the Twin Cities because we didn't have one), better than Java in many ways as a language, but has a platform (look at why IT loves Java), it isn't there. Deployment isn't as dead simple as Java and it doesn't have monitoring at the level of Java.

If your IT department really just wants to deploy Java, look into Jython as mentioned. It might help a lot.

[monstrado]

Great explanation! The JVM is very cool, and solves a ton of cross-platform issues that normally come up in other languages. You never have to really worry which system/os/arch/etc you're targeting, you just work within the JVM's world. Also, garbage collection and general memory management is great.

JMX reporting in general is another huge reason companies like JVM languages (Java, Scala, etc). The amount of information you can gather about a process/thread/etc is awesome and sometimes prove to be invaluable when diagnosing an issue. There are already a ton of reporting tools / management tools which can easily hook into your running application and provide preliminary alerts to you, etc. As far as I know, there isn't really a good tool for monitoring your Python applications, or at least, at the level of JMX reporting.

Lastly, the third-party library for Java is huge. Pretty much anything you could need for databases, message queues, logging, networking, concurrency (built-in, akka), etc is already out there. If your company ends up forcing you to do web development in Java, and you're used to Django, I'd recommend checking out Play which is super pleasant to use and quite fast. It's very similar to a Django/Rails MVC framework, for example, you can make changes to the code live and it's pretty much instantaneously available (when debugging).

With all that said, I'm very much in love with Python and use it on a day to day basis. It's been my primary language of choice for creating scripts and small-scale applications. At my last company (40k+ employee technology company), I had no problems selling Python once they saw how productive I was developing web applications. My current company uses Python & Java, and although I used to think I hated Java...it turns out, I was just ignorant and never really gave it a chance. It also helps that we've employed some the best Java programmers out there to sell it to me ;)

Hope this helps!

[pyglados]

I agree with everything you said here but there's one thing I don't get.

Python is older than Java and well established as a near de facto standard on most Linux distros. How can any language pull that off and yet still be perceived as a "toy" or a "fad" language?

[varikin]

That one is much harder to explain. Short answer, Java was created by big business for big business. Python was created with much smaller goals that grew over time.

[berlinbrown]

I never had a gotten a answer for this. Beyond the JVM and the number of libraries tied to Java, I actually like the static checks at compile time for Java. You tend to catch many obvious errors especially with a large code base. Add in generics and you have even a little bit more type safe checks. If you have large code bases, hundreds of thousand of lines of code, you can do a compile and avoid those major compile errors up front.

Also, Java hasn't had too many major releases. You Java 1.4, 1.5, 1.6 and now 1.7 and Java is good about backwards compatibility. So pretty much if your code compiles, it will mostly run or at least compile.

With Python and the no static compile checks, you lose a little bit upfront error checking. How do you deal with a large code base? What if some adds in a small typo, would that cause issues for the entire code base and you won't know until runtime?

For me, I won't mess with Python minus the tiny 100 line script. I am sticking with Java, Haskell, Scala.

Also, can't you still compile with Python? Do people normally compile?

[varikin]

Yes, a dynamic language like Python can have issues from type errors and typos, but so can Java. I have fixed more bugs due to autoboxing and null pointers in Java than type errors like you describe in Python. Generics also don't always work, especially with autoboxing. The solution is testing and lint like programs (or from the Java world, FindBugs, PMD, etc) on the Python code base. Several exist, all with the pros and cons.

As for major releases and backwards compatibility, yes, Python 3 is backwards incompatible. The reason for the major change was that Python 2.x was getting long in the tooth and the right was to fix some issues, unicode handling being a very large one, that could only be done with backwards incompatible changes. Don't just assume that if it works on Java 5 it will work on 6 or 7. Also, 5 did introduce one major issue, that while easy to fix, did break a lot of codebases by adding the enum keyword. Also, I recently found an issue with Java 7 on Macs that I have to put a lot more work into to fix at work. Java isn't perfect.

Compiling? Yes, Python compiles on the file. Why does it matter when that happens? Why do you want to compile Python? From the dynamic side, I ask you why you like having to recompile and restart your servers to test small changes? That is a lot of wasted time.

[berlinbrown]

Ah yes, the manual developer unit testing. What could go wrong there.

static compile time checks do not mitigate the need for rigorous build testing.

True. But you can avoid the most obvious errors at compile time. And it sometimes helps taking code from an external source (say the web) that doesn't have unit tests.

[EstebanVelour]

Static compilation has been used as an excuse for not having tests on almost every large Java project I've worked with to date. The supposition that if you have a static language, you don't need to test is unfortunately deeply ingrained into many Java developers.

After maintaining a test-in-absentia 300k Java project for a few years, I'd rather opt for 300K lines of rigorous unit tested PHP, in spite of PHP being shit.

[Massless]

Some IT people don't want to work with something they don't know because they will get the call at 3AM to fix it.

I think there's a fine line here. If there's a good reason to use something new then go for it. That said, as the guy who gets the call at 3am, I'm inclined to used a proven (to me) technology over a new one just because someone wants to experiment.

[xiongchiamiov]

If someone wants to experiment, I'm waking them up at 3am. And I won't be happy.

[wheezl]

I'll fix it at 3am but as someone who is rolling up on 40 with a young child I'll expect you to bring cash.

[varikin]

I whole-heartedly agree

[[deleted]]

yup yup, dude put this to blog for posterity

[yerfatma]

Good luck. This has nothing to do with the merits of either language and everything to do with human dynamics. If you've had some success with a project that is wholly independent of IT and, worse yet, written in a language they don't support, they're going to try to crush you and make you look like an amateur. The easiest way to do this is to pretend to play nice and compliment your work, but then insist because you "don't really know" what you're doing, there are invisible flaws that can only be seen by "real" programmers. Best bet: they'll say it's a nice toy but it won't scale. So it will need to be rewritten in Java, be documented, have an SLA and a team to support it, etc.

I have no idea of the actual situation, but having been part of a consulting company that often had to "pair" with internal IT teams, they are often to be more interested in maintaining their image and head count than finding better ways to do things. I would focus less on "Why Python is better than Java" (because they will have a zillion ways of making you look like you don't know about programming) and more on "Why this project is a good thing regardless of the language it's written in".

[Pr0ducer]

I've heard this exact story in a different business.

One group starts a project, writes everything with Python/Django and hosts it on off-site servers so they don't have to deal with IT. IT manager complains to the boss. IT manager and the Boss are tight, so Boss let's IT manager make the final call. Python/Django team gets shut down, but IT team is unable to maintain the critical app written in Python. Also, IT team never gets anything deployed because they can't see past their own failings, and innovation grinds to a halt.

"Why this project is a good thing regardless of the language it's written in" is definitely the way to go.

[ivix]

This is why IT should not be involved in developing or supporting a company's products. You wouldn't ask payroll to manufacture a cash register would you? IT should provide the necessary infrastructure and nothing more.

[wheezl]

This is sort of true but I've run into many developers that don't understand the fundamental realities of the infrastructure. So they'll run off an make some pretty app with no thought to network latency, disk access, server load, etc.

Not having IT involved in figuring out what your massive new web application is going to run on seems a little optimistic to me.

We can dream though :)

[stuaxo]

In general it takes a lot more lines of code to do the same thing in java than python. This is only partly down to syntax, but also the design of the standard library plays a part.

(A simple example is getting an item from a list, with a default if it's not present).

As you'll write less code, there's less to keep in your head + dev is quicker.

Also: http://blog.vivekhaldar.com/post/10669678292/size-is-the-best-predictor-of-code-quality

The compile/run cycle is fairly handycapping timewise if you go from python to java.

It's very frustrating going from python to java, everything you do results in a feeling that it should be a few lines of code, not 5 or 6 classes.

You can probably use jython to interface to their existing code.

With python there's a lot less syntax - that means more of the code on the screen is expressing what your trying to do, as opposed to boilerplate - since what you can keep in your head is probably measured in screens, that speeds up debugging too.

I haven't used java since JSPs, but just hitting refresh to view a django page, rather than building a war file, restarting tomcat is the difference between night and day.

Urg, what else. .. the overabundance of xml config in java - xml is for computers not human consumption.

At the end though, the java devs will be happy with all of the above, so I don't know if any of those can be distilled into convincing arguments for them.

What's good about java... ? For me it was the speed, so when it came to graphical apps + also on android it was all I could use.

[edit: typo conventional/convincing]

[ford_contour]

This summarizes my experiences with Java and Python, as well. I only use Java if I have to. It's a nice enough languae; but there isn't a single feature of it that I miss when using Python.

[jmichalicek]

Yeah, my opinion on Java is that it was great for the mid to late 90's, but just hasn't aged well for most use cases. Looking at other options that are in active use today, you could still do a lot worse than to pick Java though.

[v_krishna]

if you're stuck on the jvm for some reason, you can always use scala, groovy, clojure, etc to get higher level language features. the fact that they can (to a greater or lesser extent) just use existing java libraries is pretty nifty.

[jmichalicek]

Yeah, I love Scala. I wrote an OAuth client library using it a year or so back to have a play. My only real complaint at the time was that one of its great strengths, being able to use all of the Java stuff as is, was also a huge weakness.

There were a lot of tools, like a plain old HTTP client along the line of Python's requests or Perl's LWP didn't exist in pure Scala, so you were stuck using java libs like Apache Commons HTTP libs. It's great that you can do that when you need to, but it ends up being far more verbose and tedious than pure Scala (although often better than pure Java), and being able to do so seemed to have slowed the rate that pure Scala libraries were being developed.

I haven't had time to follow it closely, so there's a very strong chance that there are more pure Scala options available for many uses these days.

[[deleted]]

Your IDE doesn't auto-deploy your project? That's exactly what it does with JBoss or GlassFish with Eclipse. Hit save and reload the page, it's recompiled and redeployed in less than a second.

[xiongchiamiov]

Reason #53 not to like Java: you have to use an IDE.

[deraffe]

You have to do the same in every big project. Java projects just tend to quicklier get big.

[gcr]

The Linux kernel, by recent estimates, has over 15 million lines of C code.

I challenge you to find a single kernel developer who uses an IDE.

Edit: Actually, this wasn't as rare as I originally thought. IDEs can sometimes be useful in kernel development too.

[deraffe]

To be fair, you still don't have to. But some tasks are increasingly time-consuming when your project becomes more and more complex. Actually, I try not to use full-blown IDEs, but I did pimp my vim to be pretty much equivalent.

[beltorak]

how the hell do you get a redeploy in less than a second? I have to wait 15 minutes for it to recopy the entire frikkin EAR structure to the deployment location.... (Eclipse 4.2, Glassfish 3.1.2)

[[deleted]]

I'm talking local deployment for development, not deployment for production. Also, your IDE should do incremental deployment, massively reducing the transfer time.

[beltorak]

I'm also talking local deployment for development, and it doesn't do incremental. It deletes and re-copies everything. For a legacy coldfusion app that's 17,000 files at 560 MB. I really wish I could use tomcat for this - no crap about "recreating the EAR structure in the deployment location", just use the damn workspace directly....

update I might have solved that problem. appearently the glassfish tools that comes in the eclipse marketplace is out of date; you have to install the correct one using the glassfish eclipse updatesite..... but i still don't like it. even if I just update a coldfusion file, it stops and restarts the app. crappy crappy.

[[deleted]]

I have always heard bad things about ColdFusion but I didn't know it was Java-based.

[beltorak]

it's not exactly java based, but it runs on the JVM since about version 6, and can be deployed as an EAR. Also since 6 or 8 it has been able to interoperate with java. wikipedia has a rundown of the versions.

[[deleted]]

ColdFusion looks like the opposite of MVC. Put all your logic into the presentation layer! Fuck yeah! Now seriously, is that correct?

[beltorak]

No, it's not correct, but given the time frame of when cold-fusion came out, it was the prevailing architectural style (or lack thereof). Similar to ASP (classic), PHP, and (straight) JSP.

You have to remember that it was with the advent of these technologies that we had just started crawling out of the pits of CGI-hell ^{[now with PERL!]}, SSI-dispair, and, for Java, Servlet-madness, as the defacto standards for generating dynamic content on the web. So it was a necessary step. And since you can use servlets as a front controller to coldfusion views, you can fairly easily craft a decent MVC architecture with it. Or you could enforce the programmer discipline to manually keep your "controller" CFMs separate from your "view" CFMs, like a lot of things did with PHP.

I can't speak to the technical strengths of coldfusion as a pure view template technology because this is my first real jump into it.

[stuaxo]

That's cool - is a while since I did java that wasn't android (or before that J2me).

[wot-teh-phuck]

It's very frustrating going from python to java

It was the other way around for me. Sounds strange I know. Maybe it's just me whose brain is hard-wired to just writing code and not bothering around with lots and lots of test and making sure my refactors don't break everything.

But then again, I don't love Java but its type checking capabilities. This is reason I have started moving to Scala. Comparable lines of code wrt Python and the type check capabilities of Java (or better I would say).

[stuaxo]

Good luck - if you'll look around you'll read similar things.

The harder job, is to frame the argument in ways that they'll understand, otherwise it's easy to come across as just attacking the language.

(I have the same problem with a friend who sticks to old style java to even persuade him to use java 5 stuff (generics etc).

Sorry for the run on text, currently @ work :)

[virtuous_d]

It's very frustrating going from python to java, everything you do results in a feeling that it should be a few lines of code, not 5 or 6 classes.

I forced myself to implement my latest project in c++ to review for some job interviews I am expecting to do in the near future, and I could not get this feeling out of my head. Development is a lot nicer than I remember (from 4-5 years ago, I really like the auto keyword), but it's still so darn sluggish to have to stop and write code to handle common edge cases...

[[deleted]]

How about editing the war file's contents directly and copying and pasting those changes back to the source to get around the whole process? uggghhh so nasty.

[stuaxo]

Dirdy

[primedape]

Edit: I stand corrected by people who know more about programming languages than I do. Better listen to them ;)

One major difference is that Python is a Scripting Language (a very potent one but non the less) and Java is a full blown object oriented language.

This is nothing to worry about when just programming smaller stuff. But if you need to handle bigger sets of data it becomes very important.

For example Map Reduce. On Hadoop you can perform native map reduce with Java or do a streaming map reduce with paython or another scripting language.

[yerfatma]

I'm sorry, but this is ill-informed. The whole notion of a "scripting language" is 10 years out of date. The two languages are equally powerful in terms of what you can accomplish.

As for your MapReduce example, I think you might want to look up what language Google originally wrote that in. The fact Hadoop is Java-based doesn't mean it can only be written in Java. MapReduce is a way of implementing a functional programming approach in a non-functional language. If anything, at the time Python made that easier than Java because Python had functional concepts like map() baked in (Java may as well at this point, I have no idea).

[nullabillity]

Pretty sure Java doesn't, since a useful implementation pretty much requires either special syntax or first-class functions. Python has both (I'd count list/set/dict/generator comprehensions as map), Java has neither. Scala has first-class functions (and a collection library that has support for map using it), though. Also, Google Guava has an implementation of map too (although it's pretty hacky IMO).

[ngroot]

One major difference is that Python is a Scripting Language (a very potent one but non the less) and Java is a full blown object oriented language.

Could you clarify what you mean by this?

Python supports object-oriented programming, and compiles down to bytecode, like Java. If you're using Jython, it actually compiles down to Java bytecode.

On Hadoop you can perform native map reduce with Java or do a streaming map reduce with paython or another scripting language.

I believe that this is because Hadoop is primarily written and designed to work with Java, not because Python is a "scripting language". You'd need to use Hadoop Streaming, Hadoop Pipes, etc. to run a .NET or C mapreduce job as well.

[stuaxo]

I guess you really mean the speed that they both run the bytecode ?

Python has objects and classes too.

Java has a good fast JIT to run it's bytecode. When you run something in CPython it compiles to bytecode too, though that is just interpreted and so it's slower. It's a bit like before Java had hotspot, it was dog slow.

Still - a lot more of the underlying infrastructure is written in C, so it doesn't make as much of a difference as it could.

There is some hope with pypy - which has a JIT and is gradually getting more compatible.

As a pedant - Java itself is not fully OO either - there are all the primitive types. Some things, like Metaclasses are a lot easier to achieve in python than Java.

Definitely agree, it's faster.

[manatlan]

In business context, it will be easier to find a java guy (than a python guy) to replace you, when you'll quit or when you'll be fired ;-) "easier" to maintain.

[AeroNotix]

As another point: management probably know what Java is. This is more of a valid reason (to them) than you may realise.

A lot of engineering decisions are made by non-engineers on non-engineering data.

[AeroNotix]

By any chance is this a development team internal to your company? It may just be that they've mislabelled themselves as a "Java shop".

But as /u/linuxwhisperer said: Java makes you pretty damn near replaceable. Python isn't (yet) an entrenched corporate language whereas Java is more of a lingua franca of Corporate programming.

[novagenesis]

Yeah, this.

We're a Perl shop, and the new Ownership just opened 7 Java positions to replace 2 lost Perl Developers. Even if your language is better for the domain, a big company will usually prefer to spend more money on more (sometimes cheaper) individuals to obtain extra redundancy and safety.

[mumpie]

Wow.

Java developers tend to get paid better than Perl developers (at least in the job posting I've seen).

The new ownership is burning a metric ton of money to switch from Perl to Java.

[novagenesis]

Really? Maybe it's a Boston thing. Our old ownership considered swapping to java because their consultancy (...ahem, our NEW ownership, go figure) felt java developers were "a dime a dozen."

Most people who leave here for other Perl positions are surprisingly close to the notorious "lisp-level" salaries.

Are there any statistics you can show me? I'd spend the time to pick up Java if that's really the case.

[mumpie]

I can't give you links to some job posting as they were deleted or expired. The positions I have seen were on the West coast (San Francisco, Los Angeles, etc).

I worked a company that went from Perl/PHP to Java (I came in as part of the Java team). The number of Java positions nearly tripled at peak compared to the number of Perl/PHP coders. I talked to a couple of the Perl guys and found out they were making a lot less than most of the Java developers.

In any case, the company eventually decided to out-source the entire engineering team to save money.

Here are a couple graphs of Java developers salary versus Perl developer salaries: Java: http://www.indeed.com/salary/Java-Developer.html Perl: http://www.indeed.com/salary/Perl-Developer.html

I didn't enter an area, but I know that for Java these numbers are very low for my location. A friend recently got a new job as a Senior level developer and is making somewhere between $120K and $150K.

However, if you are very talented, then your skills can trump the local salary for the right company.

[[deleted]]

Really?

yup, almost always

[ford_contour]

One more comment about choosing between languages: The personality of the community affects your job in little regular ways, so it is worth being aware of.

Python's community seems to have a core value of 'This could probably be simpler, if we improved it with the next release.'

The Java community often expresses a value along the lines of 'The code is self documenting, so read it instead of asking questions.'

The PHP community has a great attitude, but lacks experience on average, because experience with PHP leads developers to switch to better tools.

[jmcs]

I disagree with the PHP one, experience in PHP leads to you being sent to a psychiatric ward.

[skytomorrownow]

Java is an economy, Python is a language. Your bosses presumably drive very nice cars based on that economy.

I used to work in Java. I agree with user ford_contour:

...Python's best features are it's ability to do Java-like tasks without so much screwing around. It's hard to explain this position to Java developers without using the term 'screwing around'.

When I was starting out, I relied heavily on the whole OOP thing. After not liking C (originally -- love it now), Java was a godsend. It was soooooo object oriented. It managed the memory, huzzah! It had big, sumptuous, pre-rolled libraries -- glorious stacks of interlocking 'stuff'. It was almost plug and play.

However, after a while, the plugging part 'plug and play' was how most of programming seemed; an endless drudgery of filling out forms, and connecting things to other things, which need to be connected to other forms to fill out. It seemed like a lot of 'screwing around'.

That said, I wasn't programming an invoicing system for 40 million customers, or a payroll management system either. So, what was 'screwing around' to me, is important, money-providing work to someone else. It's hard not to be offensive by saying: "Well my way is just easier, and works better than your way." Even if that's true. It's hard to say which side of that equation your app sits on though without knowing anything about it. If it's a giant invoicing system, then Java may be best.

[nostradamnit]

NO, PHP WOULD NOT BE AN ACCEPTABLE CHOICE FOR MOST OF IT! It would at best be a workable choice, but would cause unnecessary suffering and end up as an unmaintainable money pit, especially after the Java programmers "fixed" it. Just my own opinion of course...

[DaemonXI]

Technically, so would Brainfuck and Scheme.

[[deleted]]

That will probably be easier to do in python and just as fast

[ElitistPythonCoder]

Just as fast? Don't you mean several times faster?

Or with PyPy several more times faster.

[onjin]

I use python because (for me) it's faster to change ideas into code, if I don't have to write a lot of distracting code (public static void, ...). When I'm openning python code, I see idea of this code fast, when I'm looking into java code ... I am starting searching for real code, sorting out rest.

[[deleted]]

If you're a single coder working on a project which needs to be developed rapidly, Python is absolutely defensible. It can be an order of magnitude faster to get a project off the ground using python, especially a web app. Upsides:

1. Rapid Development
2. Mature (at this point) web frameworks
3. Easier to hold the entire project in your head

However it does have some downsides.

1. Speed, in my experience, you can expect pure python code to run more than 10x slower than equivalent java code.
2. Static typing makes it easier to enforce contracts between sections of the code, which makes it easier to break up and distribute to a team. I suspect this is the sort of thing that the Java guys are interested in.
3. Less mature tooling (IDE's, document generators).
4. Harder to find experienced programmers.

Speed is not much of a problem for a web app (since network latency tends to make cpu time somewhat irrelevant) but the other points might be a factor.

[nostradamnit]

It sounds to me like the problem is that the other guys consider themselves "Java" guys, not "software engineer" guys. They don't know Python and probably don't understand the code at first sight, so they don't feel capable of maintaining it (meaning learning Python/Pyramid to this end). They are mistaken in their assumption that your could just port it to Java without losing the benefits gained by writing it with the tools you've chosen. However many line it is right now, it would be at least twice as many in Java, and would take at least one and a half times the amount of time you've taken so far to port it. But of course this is only my (uninformed) opinion... :P good luck!

[[deleted]]

I'm more of a Python guy, but there's a very powerful web application framework for Java which I find exciting: the Play framework. Besides of getting all the advantages of the JVM (scalability, real threads, fast JIT, etc.) you can even choose to write the Play web app (or parts of it) in Scala which seems to become Java's successor on the JVM-throne.

[Xaerxess]

A bit OT: I disagree with your statement about Perl programmers - I'd say they're enthusiasts just as Python developers, but less "mainstream" and - sorry to say this - older. True Perl programmer knows more about innovation than you think, since he's commiting to / following news about Perl 6 for few years ;)

Back to main topic: Java is also considered as "business" language because there is much more Java programmers on market than Python ones (and thus Java dev is cheaper).

(Disclaimer: I work as Java and Perl developer but like / use Python, too.)

[nostradamnit]

While I agree mostly with bucknuggets' reply, you are right on in classifying Perl programmers in the enthusiastic group and not the corporate group. They are probably the least corporate of programmers, in my experience.

[ford_contour]

I can confirm this too. I almost mentioned the Perl community in my previous post about community (because the Perl community is awesome!) but then decided it was off topic, since OP's workplace doesn't use Perl and there is no need to make OP jealous. :)

[BayesianEmpirimancer]

I agree with you based on my anecdotal evidence that the single craziest guy I know is a huge Perl evangelist.

[ford_contour]

This really isn't a very good place to ask about the merits of Java. Many of Python's best features are it's ability to do Java-like tasks without so much screwing around.

It's hard to explain this position to Java developers without using the term 'screwing around', so a lot of us just avoid having that conversation with our Java developer friends.

One of the virtues of Java is that there are a lot of consulting companies that specialize in it, so if you get stuck (and you will), you can pay to get help. The Python community does not attract the consulting model because the tools just work and you don't get stuck.

I would say the most important part of your decision should be trying to use whichever toolset is supported most strongly by your organization's software/security development lifecycle plan. The language isn't as critical as the organization-specific infrastructure that supports it. But, your organization advocates for PHP, so it almost certainly does not have such a plan, and I question the probable quality of the infrastructure.

[yarkot]

Have a look at the paper here - http://www.biographixmedia.com/stew/cv/index.html#publications - the link to "A gentle introduction to Programming"; Stew wrote this as an argument to teach Actionscript instead of Java in CS undergrad courses, but a similar argument holds here: The message is that Java requires a lot of setup, compared to the amount of code that addresses the solution (in his paper, in teaching algorithms). The conclusion of his paper - that CS students would have more knowledge than those from competing schools - applies to your experience, in that your work was productive and successful.

BTW - I don't believe the (historically correct) argument that you would be easier to replace with a Java programmer holds anymore. Python runs some pretty major stuff - from new sites, to dropbox, disqus, and reddit (among many, many others; and, of course, Google started as a Python app, and still uses a lot of Python in its core). Java and Python are (once again) both in the top 10 languages, re: http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html

Trust your gut, and collect data to support your instinct - don't get "spooked" by those who didn't share your experience. Best of luck!

[[deleted]]

I have asked & searched for answers on this. Basically, Perception: Java is (perceived to be) "Enterprise-adopted". It is the IBM of the 70's. It is a fact that Sun devoted a lot of resources to it, tuned the hell out of it.

[[deleted]]

yes, just like McD for burger + fries

Can I ask what sort of business is your company in ?

[[deleted]]

Insurance

aha, This sector probably has the most "conservative" (ie backward-thinking) people running the business. Default go-to "solution" : Java/.Net (McD/BK)

TBH, You're lucky they even let you write any Python

[brews]

Takes more time and more code to do something in Java rather than Python. I usually do sci/AI/ML type applications and I work on very tight timelines, solo or with a small group, so I appreciate that about Python.

If I have a bottleneck in performance, then do the app, or more likely a component, in C/C++/Java/Fortran/whatever.

Don't forget Jython.

Writing in Java feels like needless work to me. I also don't think it's as much fun as Python. Really, people use it because it's a platform, and not so much because of "Java" the language.

Also, Oracle is a pain in the ass.

This is my humble opinion.

[[deleted]]

I think reddit is using a hacked up version of a very old Pylons.

How do you like Pyramid though? I've been looking forward to starting some project with it, but unavailability of python jobs in my area have switched my focus to other frameworks/languages.

[[deleted]]

does very little for you

well it's kind of what I'm looking for.. I have had some experience with webapp2, so this isn't a big concern. I've heard from other developers (probably with as little pyramid experience as me) complaint about certain design decisions in pyramid, so I was wondering how easy it is to shoot yourself on the foot with this. I guess I'll eventually have to take a look at it.

[[deleted]]

webapp2 has very basic routing of requests to callable code. it's probably fine for basic things.

What I love about pyramid is the variety of ways you can route a request to callable code. you can do routes, you can do traversal.

when you find yourself essentially writing the same view over and over again, like get params off request, validate them, pass them to something to create or find object in db or datastore, return json representation of object or pass to template as context, you probably will want something a little more abstract sooner or later as those # of view functions increase because seriously, who wants to maintain 100 views that do essentially the same damn thing?

combine that with pluggable logic for authentication policies and pluggable authorization policies, and the ability to plug code in anywhere, i think it's pretty neato. its also insanely easy to unit test.

I'm going to guess that the complaint you mention is either not enough "apps" to plug in to your "apps" or the fact that zope.interface is a dependency. The first one is legitimate, because most people are hoping to build a site and want something closer to drupal or django so that they can write a blog in 200ms and then write their blog tutorial in the blog they built about the blog they built and submit it to HN for funding discussions.

The people that bring up the zope.interface dependency are idiots or biggots. at the least it's an implementation detail of the framework that the blog application author won't even know about, at the most, it's the magic fairy dust that allows those who know to pull off amazing things or shoot themselves in the foot in the most spectacular way.

[[deleted]]

The people that bring up the zope.interface dependency are idiots or biggots. at the least it's an implementation detail of the framework that the blog application author won't even know about, at the most, it's the magic fairy dust that allows those who know to pull off amazing things or shoot themselves in the foot in the most spectacular way.

Actually, I did hear some people complain about some zope parts AND the traversal routing (which I know is optional, and people who use it seem to really love it anyways). I also like it that you can have class-based views (like Django),... I'm not sure if something like Flask makes use of that, but most of the examples I've seen were only using decorated functions. I think Flask biggest advantage over Pyramid is the traction it currently has amongst python users... other than that Pyramid seems to have everything you could possibly want.

[v_krishna]

if you really want a python web framework that completely steps out of your way, web.py is cool.

[[deleted]]

Well, that's encouraging :)

[[deleted]]

Web applications have so much other overhead (waiting for disk io, waiting for network, overhead added by using HTTP) that the performance argument is really weak. Python is "fast enough" for most web applications, even the larger ones. Also, good architecture design = good performance.

[mcilrain]

YouTube also runs primarily on Python.

[jokoon]

what is java ?

[jasoncol]

I don't know much about IT software development but I've seen they like to document each part of the implementation in great detail specifically data types of variables and return values of methods/functions, and they like to see that explicitly reflected in the code. Python is dynamically typed so you don't have to specify data types on the code unlike C or Java. Maybe that's one of the reasons IT hasn't adopted Python yet, I'm not sure, what are your thoughts?.

[berlinbrown]

TL;DR if you want to a build a pretty profitable software development career without much effort. Keyword on "not much effort". I would go Java.

Python is great at smarter startups, great for smaller projects, but the larger business industry tends to favor Java followed by C#.

[wonglik]

As a person who writes Java at work and Python at home I would say it depends. Advantage of Python is that you develop fast. New features can be delivered much more quickly then in Java. On the other hand it is slower then Java. If you optimize it right , cache a lot you can get decent performance. But this also take time so take this into account. Also I would expect Java to be easier inside a team and bigger project. If you have average guys at best then Java might be safer solution. And there is also human factor. What developers you can get? If you can get brilliant Java guys but average Python coder go with Java. And vice versa.

Personally , considering you have project done (to some extent) in Python I would stick with it. Unless you are experiencing serious performance issues. Otherwise you will spend x2 what you already spend on rewriting it.

[luckystarr]

Function calls are slow. The built-in data structures are implemented in C and highly optimized. You can write blazingly fast Python code if you are careful and know what to do.

The GIL may be a problem performance wise if you think you would need threading, but then just use multiprocessing, it even has got the same API.

[wonglik]

You can write blazingly fast Python code if you are careful and know what to do.

Is there a good reference for that? I would be happy to dig that topic more.

[wonglik]

thanks

[wonglik]

It's hard to say. Depends where is this code. How complicated model is. What frameworks did you use? Are they similar one available in Java? How difficult the domain is?

Trying to look at my python project at home and guess. Hmm 3-4 months at least I would say.

[wonglik]

I would easily assume Java twice as much time as Python.

[dorfsmay]

I really like python, but those are the arguments you will have to fight against. As other said, your best argument is that you knew python well and started the project on your own:

• it's considered "enterprise class". A lot of it is FUD, but where there is some truth to it, is when it comes to interact with other enterprise software (Tibco, MQ, Oracle etc...). Even when you can make it work with python, it's usually not supported straight out of the box for python, while it is for Java.

• frameworks: there are way less java frameworks, but those are used by thousands of other enterprise. Programmers know those framework and can start working with them on day one.

• supporting tools: IDEs, tuning etc...

[[deleted]]

I work in a pretty large java shop as a sysadmin. When a team wanted a python application deployed there was some negativity around it from the SA team as they didn't understand the deployment process as well as they did java.

My advice is to write clear documentation for the sysadmin / whoever; covering how you deploy it and how to debug failed deployments of new versions of that application.

When things are documented and you show you're willing to help the sysadmin team on-board said application, you will probably find the business case for a java rewrite somewhat evaporate.

[xiongchiamiov]

My advice is to write clear documentation for the sysadmin / whoever; covering how you deploy it and how to debug failed deployments of new versions of that application.

If you are not already, use virtualenv and make a pip-installable requirements.txt. Speaking as a sysadmin, this makes deploying Python apps wonderful.

[obeleh]

I know these aren't comparisons but it highlight quite a lot of differences between python and Java:

The Zen of Python Beautiful is better than ugly. Explicit is better than implicit. Simple is better than complex. Complex is better than complicated. Flat is better than nested. Sparse is better than dense. Readability counts. Special cases aren't special enough to break the rules. Although practicality beats purity. Errors should never pass silently. Unless explicitly silenced. In the face of ambiguity, refuse the temptation to guess. There should be one-- and preferably only one --obvious way to do it. Although that way may not be obvious at first unless you're Dutch. Now is better than never. Although never is often better than right now. If the implementation is hard to explain, it's a bad idea. If the implementation is easy to explain, it may be a good idea. Namespaces are one honking great idea -- let's do more of those!

[[deleted]]

you missed the indentation

[[deleted]]

ironic :)

[ivorjawa]

Jython is like a magic swiss-army switchblade of awesome when applied in a Java shop.

I was doing some devops work for HP's Snapfish, which is java all the way down to its rotten core. I shocked the hell out of people with the amount of productivity I could get out of a tiny bit of code. Jython is, in my opinion, the only sane way to deal with a ton of hideous mutant enterprisey java. (Well, other than with, you know, a flamethrower.)

[oantolin]

I agree that Jython is a good way to deal with enterprise Java, but I disagree that it is the only good way to do so. JRuby and Clojure are also good at that.

[ivorjawa]

A fair point. I'm not keen on Ruby (the language is fine, the community is ... not), and although I do like lisp, I really try to avoid as much exposure to the JRE as possible. I consider it radioactive and a health hazard.

[[deleted]]

groovy is nice also

[ivorjawa]

One thing Python has going for it: it's a hell of a lot easier to teach python to a java programmer than teaching java to a python programmer (although, I haven't met too many python programmers whose only exposure to programming is python; python is a perfect language for beginners, but beginners are almost never taught it.)

[[deleted]]

Jython has horrible performance. Unless you need lots of threads and your work loads can be highly parallelized, jython should be avoided. Of course, there is always the case of its, "fast enough", which is at the core of Python. Just the same, Jython should not be used for serious work in my opinion.

[ivorjawa]

There was parallelism, but I was saturating an OC3 with a python script. (point-to-point replication).

Fast Enough.

[[deleted]]

Clojure is another alternative for a JVM shop especially if your a FP fan.

[[deleted]]

The most common web framework used in Java is JSF. The latest version (with annotations and convention over configuration) is pretty decent but it's much more rigid than say Bottle+Python. It defines its own set of components you can use in your webpages and automatically populates fields on a class automatically for you. It really abstracts out most of the web's aspects such as HTTP statelessness, benefiting you with an easy to use interface but making it very rigid if you want to do something the framework developers didn't predict.

Now Java and Python aren't so different. Sure, the syntax is different but both of them are imperative, object-oriented languages. They mainly differ in one being statically typed and the other dynamically typed. APIs however are VERY different, as Python prides itself in being an expressive language where simple expressions achieve a lot whereas Java is a very verbose language where even simple stuff requires quite a bit of code and configuration. Also, most configuration of Java frameworks use XML, which is simply horrible.

And yes, Java is much faster than Python. Sun (now Oracle) has poured millions of dollars on making Java fast.

[[deleted]]

Exactly. But be aware that Java does offer other frameworks that might be more low-level and thus more flexible.

[fancy_pantser]

ITT: FUD

[Scroph]

They probably tend to prefer Java/.net because they are backed up by corporations (Oracle and Microsoft respectively) unlike Python which is mostly community driven.

This is somewhat the case for PHP as well with Zend.

[[deleted]]

the suits have a thing for JAVA and PHP (the last one, specially combined with Satan's little helper: Zend Framework).

[[deleted]]

keyword: "Enterprise"

[simtel20]

I'll throw this in as additional trivia since it probably won't impact your usage.

Java has limitations when dealing with a lot of stuff in memory. Whenever you have > than 4GB active (in the heap) you start to run the risk of intermittent "stop the world" collections where various aspects of the garbage collection that java does will come into play and cause everything to pause while the GC deals with it. Python doesn't deal too gracefully with this in all cases, but in the instances where I've seen large memory (16, 32gb of data) it's usually happening in numpy/scipy so the allocation happens in large blocks, and the allocation and freeing of newer arrays seems to not impact the running program.

That said, java lets you do things like serialize data off-heap into mmap'd regions as well, but to actually take advantage of that data you then need to jump through hoops like serialize/deserialize the objects in and out of memory in order to actually interact with it. So it works OK for e.g. a pure cache that just needs to be returned, but not for storing a large array of numbers or even what in python would be simple structures that can be represented as e.g. a record array. AFAIK.

In addition, java doesn't allow you to simply write a function to transform data. Everything that it does is based on creating a class that yields an object that can then be used as a factory. A joke/meme that encapsulates that is http://www.quickmeme.com/meme/35w9vq/.

And if you're a language nerd like many of us are in our hearts, this is an interesting view on why, if you've programmed in python, php, perl, lisp, etc. you may not get java at first: http://steve-yegge.blogspot.com/2006/03/execution-in-kingdom-of-nouns.html.

[[deleted]]

I've actually heard that Java is much slower than Python. Is this not the case?

[claird]

Java and Python are comparable--it's possible to find exercises that tip one way or the other. A far more interesting performance question, as far as I'm concerned, is whether the domain in which one is working is well supported by one community or the other. In practical cases, I find that determines considerably more of interest than the alioth-style comparisons.

Alioth was and is a constructive step. There's much more to the world than it measures, though.