Python now uses Mercurial

http://hg.python.org/cpython/

by jonknee • 15 years ago

137 111 15 years ago

hg.python.org

js22• 15 years ago

I was confused why this was news since the decision was made two years ago:

http://mail.python.org/pipermail/python-dev/2009-March/08793...

But I see from http://www.python.org/dev/peps/pep-0385/ that it's taken that long to migrate away from svn.

geekam3• 15 years ago

But why are they using Mercurial and not Git? I want to what are the advantaged for them to choose Hg.

koenigdavidmj• 15 years ago

http://www.python.org/dev/peps/pep-0374/#why-mercurial-over-...

Basically, they wanted a tool that was equally usable on all platforms, which excluded Git on Windows.

They also wanted something written in Python, of course, although they would have sacrificed that in the interest of pragmatism.

pestaa• 15 years ago

In all fairness, I'd like to point out it's quite possible to make Git work on Windows. If one can adjust the path, it is also reachable through the same command line Windows folks are used to.

cageface2• 15 years ago

If nothing else it's because Mercurial itself is written in Python.

random42• 15 years ago

Not true.

While mercurial being written in python is noted[1] , it is made explicitly clear, its not the reason behind the main selection of Hg as the version control.

[1] http://www.python.org/dev/peps/pep-0374/#why-mercurial-over-...

xi• 15 years ago

See http://www.python.org/dev/peps/pep-0374/ for the rationale; but keep in mind it's more than two years old so some of the criticisms may not longer apply.

null_ptr• 15 years ago

Why would Git be any better? They're both tools that ultimately accomplish the same thing.

Peaker2• 15 years ago

git rebase -i, git reset --hard, git checkout <any-refspec>

sid0• 15 years ago

Because Guido has a taste for good UI. </troll>

viraptor3• 15 years ago

Trolling aside, that's the only reason I chose hg over git for my projects -> sane approach to the UI. With both of them having more or less the same functionality, UI of git is... inconsistent at the very least.

tghw3• 15 years ago

I find the way your phrase that question interesting. Git and Mercurial are nearly identical in terms of functionality, to the point that converting back and forth between them is pretty trivial. (Example: here's Git's repository in Mercurial https://mirrors.kilnhg.com/Repo/Mirrors/From-Git/Git)

The only real difference between the two are the ecosystems. Mercurial, being written is Python, is very portable and easily extensible. I feel like, because of that, the tools for Mercurial are better. Git has GitHub, and the incredible open source community they've developed there.

* Note, the rainbow road is due to one of the few differences between Git and Hg: Hg does not allow octopus merges, so the conversion turns them to a sequence of two at a time merges. Also, in the interest of full disclosure, I'm one of the devs on Kiln, so I'm certainly biased towards Hg.

js22• 15 years ago

octopus merges are rare in the git.git repo:

  $ git rev-list --merges --parents --tags | awk '{print (NF-1)}' | sort | uniq -c
  4409 2
    22 3
     5 4
     3 5
     1 6

So there's been a total of 31 octopus merges compared to 4409 typical two-parent merges.

geekam3• 15 years ago

Wow! Nice to meet you. I wish my work was as interesting as yours.

alok-g2• 15 years ago

Interesting to note that bzr got close to mercurial in the votes in spite of this being bzr version 1. Version 2 is much improved in speeds (comparable to git/hg).

wh-uws• 15 years ago

I myself am quite partial to bzr espeically since tortoise-bzr uses my favorite diff tool by default

http://doc.bazaar.canonical.com/explorer/en/guide/qbzr/qdiff...

I would be interested to know about other's impressions of bazaar and why most people seem to share the same sentiment towards it as those at pycon that year

While no one said they did not want bzr chosen, no one said they did either.

prog• 15 years ago

I have been using bzr for 2+ years now. For personal projects I am quite happy with bzr+launchpad. At work, we have been using bzr on Linux.

The move from 1.x to 2.x brought in significant performance and memory improvements.

alok-g2• 15 years ago

I did detailed evaluation of bzr, git, hg and svn. And found bzr to be good too (at least equally good). Most comparisons I found online have been too old to be using older version of bzr which was very slow in comparison.

I am still unclear on the impact of a "branch" being the key concept in bzr as opposed to "repository" in git/hg.

Git's support on Windows has improved considerably (although I could not find a good GUI). So I rather find not much reason to use Hg!

jarin2• 15 years ago

It's interesting that each major web language seems to have paired off with a different VCS:

- Python + Hg

- Ruby + Git

- PHP + ...SVN?

strmpnk• 15 years ago

The C Ruby implementation is actually on subversion with an official git mirror. Granted, most Ruby projects are hosted using git repositories these days.

burgerbrain6• 15 years ago

PHP + ...SVN?

Gotta say, they deserve each other.

there• 15 years ago

and OpenCOBOL uses CVS

http://www.opencobol.org/ (http://sourceforge.net/projects/open-cobol/develop)

maybe a language older than that still uses RCS

abredow• 15 years ago

Because they both have widespread adoption?

bluesnowmonkey2• 15 years ago

You know, comments like that disparage by implication anyone who finds value in PHP or SVN. That's a big chunk of the development community. It tears people apart rather than bringing them together. Maybe you should redirect your energy from snark and criticism toward something more constructive.

dchest• 15 years ago

- Tcl + Fossil http://code.activestate.com/lists/tcl-core/10108/ :-)

sigzero• 15 years ago

That is an excellent choice for them. Dr. Hipp (author of SQLite) is the author of Fossil and a big Tcl fan. Tcl is maintained by a small core team of developers. Just an overall good fit for them.

jrockway3• 15 years ago

Perl also uses Git.

burgerbrain6• 15 years ago

And Go uses mercurial.

Groxx2• 15 years ago

- .NET + VSS?

icey• 15 years ago

TFS now (Team Foundation Server)

mwsherman• 15 years ago

Codeplex, which is Microsoft's open source site, supports Mercurial, SVN and TFS.

drdaeman• 15 years ago

- Haskell (at least GHC) + Darcs

jedbrown• 15 years ago

A permanent switch to Git for GHC and all associated repositories is planned for March 15.

jmuk• 15 years ago

So nobody is using Monotone?

l0nwlf• 15 years ago

There is a reason Python is paired with Mercurial.

Hg is written in Python. As for why Mercurial was chosen over Bazaar, it came down to popularity. As the core developer survey shows, hg was preferred over bzr.

briancurtin• 15 years ago

That's not really the reason, and I believe it's even stated in the PEP.

cppsnob2• 15 years ago

Java?

supert0nes• 15 years ago

Java is a specification, the Oracle JRE/JDK is not open source. The OpenJDK uses Hg. When they talk about Python they are talking about the cpython or main implementation. Pypy, another Python implementation uses Hg as well

stewbrew• 15 years ago

it has more to do with corporate affiliations:

hg seems to be strong at Google github was done in ruby php ... whatever

egor83• 15 years ago

Announcement in Python-Dev:

http://mail.python.org/pipermail/python-dev/2011-March/10873...

vimalg22• 15 years ago

Git and Hg accomplish essentialy the same thing. The platform support and tool/utility support for Mercurial on windows in important to note.

I decided to choose Mercurial as the VCS for my 'work'. This was a team that had no prior exposure to VC before. And works in a mixed environment. Hg follows the 'one true way' philosophy of Python; so there's just a single command to learn for each task. Plus, Bitbucket's new Free pricing plan for tiny teams convinced me to go with it for online hosting(rather than roll our own hg server over vpn)

Though, If I had to choose a host/vcs for 'my awesome FOSS community project', it would go on Github.

woogley• 15 years ago

This is basically where I stand as well. Git has no real appeal for me, but GitHub does. Plus, with the ridiculously easy hg-git[1] tool, I'm able to take advantage of GitHub while staying in my Hg comfort zone :)

[1] http://hg-git.github.com/

chousuke• 15 years ago

Heh, I'm the exact opposite. I use a hg-to-git tool to access hg repositories, because I'm much more comfortable with git.

I often hear people claiming hg is easier to use and has a better interface, but every time I have to use hg it rubs me the wrong way because I can't use it like I use git :/ (In particular, I find hg branches needlessly complicated and cumbersome compared to git's "just a pointer" model)

I guess between the two you'll end up using the one you first bother to learn beyond memorising basic commands.

int3• 15 years ago

As someone who hasn't used Hg before, I'm curious -- what are some examples of Git commands that are better executed in Hg?

mckoss2• 15 years ago

I use both git and hg - and like both of them (though I have more experience with hg). Github is far and away the best hosted distributed version control service, with a constant stream of innovative features for open-source developers over the last 2 years.

Git has had two main drawbacks in my mind. 1) Much of it is implemented as script commands, and I think it still requires you run an emulated shell in Windows to use it (by contrast, Mercurial is a pure python app, and is ultra-portable). 2) Coming from the Linux community, it seems a little heavy weight for small projects. Some command require what seem like extra steps on Git as compared to Hg. For example, Git requires that you do a "git add" before doing a "git commit". Mercurial assumes that you want to add all the changed files in your repo (or you can list the files needed in a commit).

For complex scenarios, Git's system does provide a bit more control in packaging up exactly the set of changes you want in each atomic revision.

Besides these minor historical differences, I think they both are excellent, and are really a matter of personal or team preference.

viraptor3• 15 years ago

No specific commands really, but I think the whole hg UI is just more consistent. I use both, yet with git I have to revert to `man` almost every day :/

Compare: `git branch xxx / git branch -a`, `git tag xxx / git tag -l`, `git show-ref --heads`

To: `hg branch xxx / hg branches`, `hg tag xxx / hg tags`, `hg heads`

There are also "duplicates" that I'm not sure why aren't folded into one command: `show-branch/branch`, `show xxx` which is `diff -c xxx` in many other systems, etc.

These are just simple cases, but there's loads of situations where you have to find out yet another command in git / yet another parameter to do what you want. Hg has better defined defaults and the whole list of commands looks like it was designed, while git looks like everyone just added what they needed... Auto-expanding commands in hg is also nice - I hate it when git tells me 'ci' or other short name is not a command (yeah, I know about aliases).

In some situations I also think that git does exactly what it's programmed to do... which isn't always the same as - what workflow makes sense in a specific case. For example `branch` creates a branch, but you still need to do `checkout` (or just `checkout -b ...`). Why? What's the common use case for creating a branch you're not going to work on? Which behaviour do you expect more often?

All in all, not the end of the world, but when you use the tool every day, it becomes annoying, especially if you see it can be done better.

joske2• 15 years ago

Why would you choose Github over Bitbucket for your FOSS projects? I haven't used Bitbucket yet, so I'm interested in a comparison.

vimalg22• 15 years ago

Large Hacker userbase.

epynonymous• 15 years ago

makes sense since mercurial is written in python, it's like eating your own dogfood in some senses.

tzury• 15 years ago

via Guido (http://twitter.com/#!/gvanrossum/status/44169137240551424)

For those asking "why not git", read http://www.python.org/dev/peps/pep-0374/

Python now uses Mercurial

Related Stories