Make sure you install the 64-bit version of Eclipse if you can. If so you should be able to use the latest version of Pydev without any problem.

After trying all of the listed ways to work with 1.7 I was still seeing error message when Eclipse tried to open the editors and navigators on startup. But when I created a new project it worked. Then I tried just closing all editors and reopening them and they too work. The navigator had also set itself to working set and showed nothing. When I switched that to projects it also started working.

The same thing happened to me. This is how i fixed it.

1. Click on "install new software" - it's under help.
2. Click on " what is already installed"
3. Uninstall PyDev
4. Reinstall PyDev BUT instead of the 3.3XX version, install the latest 2.XX version (i.e click on the drop down menu and select the latest 2.XX version)

It worked for me!

So I tired many of the suggestion above, and I think what finally got it to work is instal the JDK from: http://www.oracle.com/technetwork/java/javase/downloads/index.html. You might also need to uninstall the pydev plugin and reinstall it again. But after install the JDK 8, I got the Pydev to show up under preference.

menu Help > Install New Software... don't fill "works with" but click on Add... In the next screen, add the update site of PyDev and PyDev Extensions: Name : PyDev and PyDev Extensions Location: http://pydev.org/updates and go on...

pydev 3 is buggy! Use 2.8 and you should be fine.

I also had this problem, wanted to use python3.4 as interpreter and it wasn't compatible with pydev 2.8 so after a few trials I found out that if you install pydev 2.5 everything works fine !! (At least on Eclipse Kepler).

I know this thread is old but I thought I might contribute my solution because none of the suggestions above worked for my Mac running Yosemite [10.10.2]. I hope this will be helpful to someone else. Despite updating to the latest JDK my mac kept reporting a wrong version. It turns out the symlink was point to the old version and fixing that issue got my pydev/eclipse working.

1. Find out the current default Java version

   Java -version
   

2. Get installed versions

   /usr/libexec/java_home -V
   

3. Navigate to the following folder and delete the current symlink

   cd /System/Library/Frameworks/JavaVM.framework/Versions/
   rm CurrentJDK 
   

4. Create a new symlink pointing it to the newer installation substituting 'new-version' with appropriate version from 2 above. i.e jdk1.8.0_40.jdk

   ln -s /Library/Java/JavaVirtualMachines/<new-version>/Contents/ CurrentJDK
   

5. Confirm your default version

   Java -version
   

6. Restart.

Happy coding.. :)

I had to uninstall pyDev 3 and install 2.8 to get this working with Eclipse (V 4.4) and Yosemite (V 10.10)

The easiest way is just getting http://www.liclipse.com/ which has everything setup from the start... if you don't want to go that route (as LiClipse is commercial) you may want to try to specify the java 7 install manually:

Grabbed from http://pydev.org/download.html:

Well, the main issue at this time is that PyDev requires Java 7 in order to run. So, if you don't want to support PyDev by going the LiClipse route (which is mostly a PyDev standalone plus some goodies), you may have to go through some loops to make sure that you're actually using Java 7 to run Eclipse/PyDev (as explained below).

All OSes

Make sure you download/install the latest Java 7 JRE or JDK, try restarting to see if it got it automatically.

I.e.: in help > about > installation details > configuration check if it's actually using the java 7 version you pointed at.

If it didn't get it automatically, follow the instructions from:

http://wiki.eclipse.org/Eclipse.ini to add the -vm argument to eclipse.ini on "Specifying the JVM" to specify the java 7 vm.

Note on Mac OS: You can use the command "/usr/libexec/java_home -v 1.7" to get the base path for the JVM (though you also need to append "/bin/java" to the output of said command to the -vm arg in eclipse.ini).

Solution

Using standard Eclipse installation method:

In Install New Software, Add a new site to Work With. I called my entry PyDev Old and entered the Location:

https://dl.bintray.com/fabioz/pydev/old/site.xml

That has PyDev for Eclipse versions 2.8.2 to 4.5.3

Details

I am working with Indigo (3.7) and so need a version of PyDev that is older than 3.0.0. My JDK is 7 as noted elsewhere in this question. The option for Show only the latest versions of available software is turned off.

The standard advice for getting PyDev is to use http://pydev.org/updates and turn off the only latest option. That now only lists PyDev 5.

I had the same issue!

Just update all three SWs to the latest version and it will solve the problem.

Do like this:

1. update Eclipse to Luna Service Release 2 (4.4.2) 64-bit, then
2. PyDev - Python IDE for Eclipse 5.1.2 from Eclipse Marketplace and then
3. download and update the Java SE Development Kit 8u92 64-bit

It should work well now!

I had the same issue in Eclipse 4.4. Had to use a previous version of PyDev. It simply seems to be a matter of using the correct Java JRE/JDK and PyDev for the version of Eclipse you're running.

From http://www.pydev.org/

Release 5.2.0

Important PyDev now requires Java 8 and Eclipse 4.5 onwards.

PyDev 4.5.5 is the last release supporting Java 7 and Eclipse 3.8. See: update sites page (http://www.pydev.org/update_sites/index.html) for the update site of older versions of PyDev.

Oct 2016:

• Installed fresh new copy of Java JDK 1.8.0_102 took care of the incompatible OSX JRE 1.6
• Installed fresh copy of Eclipse Neon 4.6.1
• Followed pydev manual: http://www.pydev.org/manual_101_install.html

all working fine now...

First install and setup following applications as these are mentioned in above answers:

1. Jave (version 8 or greater)
2. Eclipse(version Neon/Oxygen or greater)
3. PyDev in Eclipse

Now go through following steps:

1. Eclipse -> Window -> Perspective -> Open Perspective -> Other..
2. Select PyDev in the list.
3. Click Open.

Now you are all set.

Cheers!!!

You can move back to 2.x.x:

1. Eclipse -> About Eclipse then click "Installation Details" button.
2. From "Installation History" tab choose last installation.
3. Click Revert button.

You will go back to chosen installation.

I managed to get the following to work with Eclipse IDE for Java Developers 4.4.1 Luna on OS X 10.9.5 Mavericks:

1. Download and install the latest version of the JDK (currently Java SE 8u25) from http://www.oracle.com/technetwork/java/javase/downloads/index.html. (Not the JRE!)

2. Navigate to /Applications/eclipse/Eclipse.app/Contents/MacOS (or wherever you have Eclipse installed) and open eclipse.ini.

3. Append the following to the bottom of the file (be sure to replace the version number with yours):

   -vm
   /Library/Java/JavaVirtualMachines/jdk1.8.0_25.jdk/Contents/Home/bin/java
   

4. Download the latest version of PyDev (currently 3.8.0) from SourceForge at http://sourceforge.net/projects/pydev/files/pydev/.

5. Unzip its contents to /Applications/eclipse/dropins (or wherever you have Eclipse installed) and restart Eclipse.

Hope this helps anyone who's still having the issue. Special thanks to Mohammed Lokhandwala and braineo.

Aha , It is solved just now.I show it in the following.

First , I use MyEclipse with jdk1.8,maybe some people dont know that Eclipse (or MyEclipse) has its own jvm , what is not "jdk" you downloaded and installed and the "built-in jvm" is default. You can check this out by clicking like this " Windows-->preferences-->Java-->Installed JREs" And I found my MyEclipse used the default jdk1.6 .Then I click "add" to build path of my installed jdk1.8 .

Second , I opened the configuration file named "myeclipse.ini" and check this in the following.

binary/com.sun.java.jdk.win32.x86_64_1.6.0.u43/bin/javaw.exe

Third , I replaced it with new path . Check the following out. It is new path.

D:/jdk/java/jdk1.8/bin/javaw.exe

Last , restart it .And you can find "PyDev" in "Preference".

Happy Coding with Python!

PS：Pycharm is good,and you can get it for free if you are a student or a teacher. click here

I was experiencing the same problem using java 1.7.0_101. Updated to 1.8.0_91 and "voilá"! PyDev finally appeared.

I had the same issue on Luna and found my mistake.

After checking the author in "Do you trust these certificates?" page, and I was able to successfully install pydev.

The page lets you proceed without checking it, and no error occurs and it was where I totally missed. Maybe it is useful for someone.

The PyDev.org website states (http://pydev.org/manual_101_install.html) --

"""
Important requisite

PyDev now requires java 7 in order to run. If you don't have java 7, the update 
process  may appear to succeed, but PyDev will simply not show in the target
installation. Please double-check if you're using a java 7 vm in 
about > installation details > configuration 
before trying to install PyDev.
"""

This problem started to appear in my Eclipse after I removed the Java 7 runtime from my system (because the Java code I am building needs to run on an older version of Java, but that's unrelated). After I realized that I had lost PyDev, I reinstalled Java 7 and PyDev is working fine now.

Another option would be to rollback to the previous version of PyDev that does not require Java 7, but it would require a manual installation of PyDev and I would lose the convenience of automated updates. The best way forward, it seems, to run run Eclipse on Java 7 and switch those Java projects that need to depend explicitly on Java 6 to that JDK/JRE.

How I was able to get pydev to work in mac/eclipse is download the latest JDK as mention 100 times above install it and then do the following.

1. open eclipse choose preferences > java > installed JREs
2. click on "Search..." button it will auto populate the JDK 1.7 you just installed
3. Click ok
4. have a beer!

-Cheers!

Solved.

OSX Mavericks 10.9, Eclipse Keplar 4.3.2, PyDev 3.4

Problem: PyDev not showing up under Ecplise > preferences

Solution: Download, install and point Ecplise to JDK 1.7

1. Unistall PyDev

2. Under Eclipse > preferences > Installed JREs you probably only see Java SE 6

3. Download and install JDK 1.7 from http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html

4. open terminal and run "/usr/libexec/java_home -v 1.7"

   this will return the directory in which JDK 1.7 reside, something like /Library/Java/JavaVirtualMachines/jdk1.7.0_55.jdk/Contents/Home

5. Under Eclipse > preferences > Installed JREs click "add", select "MacOS X VM", click "next"

6. in JRE Home paste your version of /Library/Java/JavaVirtualMachines/jdk1.7.0_55.jdk/Contents/Home, give it a name and click "Finish"

7. Restart Eclipse and re-install PyDev.

Voila!

Most likely you do not have java 7 or > eclipse 3.7 installed on your machine it is a requirement of pyDev 3 see here http://pydev.blogspot.co.uk/2013/11/pydev-30.html

It happened to me too, but using Debian stable (wheezy, in my case).

I solved installing doing:

# apt-get install openjdk-7-jdk

After this, I checked that I had two alternatives of Java JDK:

# update-java-alternatives -l

And the output was:

java-1.6.0-openjdk-amd64 1061 /usr/lib/jvm/java-1.6.0-openjdk-amd64
java-1.7.0-openjdk-amd64 1051 /usr/lib/jvm/java-1.7.0-openjdk-amd64

Finally, I did:

# update-java-alternatives -s java-1.7.0-openjdk-amd64

After that, I removed pydev plugin from Eclipse, reboot Eclipse, install pydev (using Marketplace), reboot Eclipse, and now it works.

Credits: http://vas.davimas.name/2013/07/switching-between-openjdk-v6-and-v7-in.html and Richard's answer, above

I just figured it out. You will need JDK rather than a JRE.

1. Download it here first:JDK Download

2. Install it.

3. Explore /Applications/eclipse/Eclipse.app/Contents/MacOS (where you put your Eclipse)

4. Open eclipse.ini

5. add

   -vm
   /Library/Java/JavaVirtualMachines/jdk1.7.0_45.jdk/Contents/Home/bin/java
   

You will change the version according to your situation. Enjoy!

After struggling with this problem for some days I wanted to share my solution to the problem - inspired by the above posts (kudo's to them).

My Configuration:

• MacBook Air (intel) with OS X 10.9
• Eclipse: Kepler SR1 installed (zip file extracted in the Applications folder)

My situation:

Tried to install PyDev via Eclipse Help --> Install new software... Installation was succesfull, but PyDev didn't show up anywhere in Eclipse.

My solution:

• In Eclipse go to Help --> Install new software...
• Uncheck "Show only the latest versions of available software"
• Select PyDev the usual way, but install the latest 2.x version instead of the 3.x version

Apparently PyDev 3.0 does not work with the default OS X configuration of Eclipse, Java and Python (don't exactly know why, though...)