Bpython is a fancy interface to the Python interpreter

by llambda • 14 years ago

187 74 14 years ago

Heh, The overall sentiment in irc freenode #python is a general dislike of ipython and a recommendation of bypthon as a good alternative to the REPL. It's a pretty light alternative but I still generally use ipython these days.

vasco• 14 years ago

When I saw ipython for the first time I was really excited but now I realize I never actually use it. Any thoughts about why it isn't appreciated?

DasIch2• 14 years ago

ipython provides more features but requires significantly more magic to do so which can have unintended side-effects e.g. by triggering stuff through introspection that the user didn't intend to trigger.

beagle3• 14 years ago

Check it again. It recently added a "Notebook" mode that you might find useful.

dbecker• 14 years ago

I think ipython is widely appreciated in the scientific/numeric python community.

sophacles2• 14 years ago

I think it is appreciated in some circles, particularly people who do programming as a means to something else (eg science research stuff). In my experience looking and playing with it tho (including diving in a bit), it just seems like a lot of complicated code for fancy repl work. Too much tight integration with their way of doing it. Personally, I was extremely interested in making ipython tie in deep with vim, but even the api provided was too complicated for the functionality it provided, given I was using outside the expected ways.

masklinn2• 14 years ago

ipython is very, very appreciated in scientific python communities.

It might be less so on the "engineering" side due to being perceived as more heavyweight?

taejo• 14 years ago

I for one found it very difficult to get into the habit of typing "ipython" instead of "python", which seems silly but really did stop me using it.

bowyakka• 14 years ago

I have never really got this, I think ipython is the best thing since sliced bread.

(Not that I dislike bpython, just never had the desire to use it)

bobfarrell8• 14 years ago

The main reason for this is actually that IPython has had (and, by design, in some cases still does have) the "problem" that code that works in IPython can work differently to the standard Python interpreter. This meant that people quite often had problems where the solution was "run it in the actual python interpreter". When I first started writing bpython one of the design goals was that all code that runs in bpython would also run the same in the vanilla REPL. This is why there is no extended syntax such as that provided by IPython (I don't actually use it so can't give good examples, but I think you can do things like "object?" to get help etc.). IPython also had some issues with unicode and encodings that may have since been resolved.

This is the only good reason I would recommend bpython over IPython objectively. Other than that, it's just a matter of taste - bpython is just a standard shell with some nice features to aid the user whereas IPython has a whole host of features and extensions and integrations that make it a great tool for lots of people. I don't think you have to use one or the other and I don't see them as competing pieces of software. IPython is a great tool and seems to suit a lot of people, particularly those in the mathematic and scientific communities.

Let me put it this way: if IPython implemented all of the features that bpython has and bpython became entirely redundant then I would only be happy that people have a great tool to help them with their development and that bpython may have played a part in helping it get to that state.

amjith2• 14 years ago

Pycon lightning talk about bpython:

http://www.youtube.com/watch?feature=player_detailpage&v...

tyler_ball• 14 years ago

Starts at 10:45

sdfjkl• 14 years ago

This is nice for just exploring Python (and modules).

plainOldText• 14 years ago

Hmm, not bad. Actually, not bad at all. Very intuitive. I wish you could change the theme color though.

amjith2• 14 years ago

Yes you can change the colors. http://docs.bpython-interpreter.org/themes.html

pconf• 14 years ago

There doesn't seem to be a color theme that works with a standard black on white xterm. All of the defaults seem to be designed for Windows' white on black... Even defining 'prompt = k' (where 'k' is black) produces a nearly invisible grey prompt. Thanks but no thanks, I'll stick with vi/vim.

xtacy2• 14 years ago

I really like the "instant" auto-completion. Can someone throw light on how it was done?

btn• 14 years ago

The code that generates the completions [1] and displays them [2] is fairly simple. It uses a mix of scanning for a function's docstring, Python's built-in rlcompleter module [3] to generate the possible identifiers and keywords, its own module scanner for imports [4].

[1] https://bitbucket.org/bobf/bpython/src/2b3fb2cb6500/bpython/...

[2] https://bitbucket.org/bobf/bpython/src/2b3fb2cb6500/bpython/...

[3] http://docs.python.org/library/rlcompleter.html

[4] https://bitbucket.org/bobf/bpython/src/2b3fb2cb6500/bpython/...

xtacy2• 14 years ago

That's very useful. I wish shells like bash/zsh had this instant auto-completion!

bobfarrell8• 14 years ago

Hi. It's done using ncurses for the display (if you've ever worked with curses you can imagine how much of a headache the whole thing was). The introspection is done using the `inspect` module for the arg spec/doc string, and either inspect.getmembers or just dir() to get the attributes (it's been a while since I wrote it). We had to do some pretty weird stuff to get the attribute inspection to not trigger __getattribute__ for objects that implement it (i.e. to introspect without side-effects) but it seems to work pretty well.

superdude• 14 years ago

FYI for Windows users..."pip install bpython" won't work. You must install the Curses binary. I suggest from here: http://www.lfd.uci.edu/~gohlke/pythonlibs/#curses

bobfarrell8• 14 years ago

I didn't know about this - we actually have a GTK version that needs some tidying up and packaging before we actually release it (if anyone is interested in helping with this that would be great as none of us use Windows - see the bpython website for details on how to get involved).

Could you possibly drop me an email or get me on IRC (again, see website for details) to let me know how this curses binary works on Windows ? It'd be great to add some documentation to the bpython site on this.

dustingetz• 14 years ago

is there a good emacs-mode for python that gives interactive development of the same level as inferior-lisp[1]? the python-modes i've seen only let you re-execute a file, but not a buffer or expression.

inferior-lisp makes all the problems bpython is trying to solve, irrelevant.

[1] example: http://vimeo.com/22798433 (4 mins)

ramanujan• 14 years ago

I patched python-mode to do this (also did something similar for node and a few other interpreters). Main thing is to add a "py-execute-line" routine and a few others as wrappers around the file execution code. If there's interest, might post as open source.

EDIT: here is a snippet

  (defun py-execute-line (&optional async)
    "Send the current line to the inferior python process using py-execute-region."
    (interactive "P")
    (save-excursion
      (end-of-line)
      (let ((end (point)))
        (beginning-of-line)
        (py-execute-region (point) end async)))
  )

That's the py-execute-line function, which is sending code to py-execute-region defined in python-mode (http://bazaar.launchpad.net/~python-mode-devs/python-mode/py...).

For some reason the default python mode in emacs is python.el rather than python-mode.el. So you probably want to start by using python-mode.

RBerenguel2• 14 years ago

Standard python mode has also region evaluation and definition evaluation, which mostly account for that. Maybe I'm missing something here? What do you want from inferior-lisp that you don't have in python?

eddie_the_head2• 14 years ago

This looks very nice, but you'll notice the Arabic unicode sample is rendering left-to-right, as almost all terminals currently are. I haven't seen any terminal beyond right-to-left specific ones that support proper Arabic yet :/

hasenj• 14 years ago

You're complainimg to the wrong audience.

I rarely need Arabic bidi support in a shell, and if I do, I tend to copy paste from a proper text editor.

eddie_the_head2• 14 years ago

Yes, I agree but I don't do any Arabic editing in terminal. The only time I bump up against this problem is when in Arabic IRC channels with irssi, and all the letters are separated and backwards. I usually switch to IRCCloud's web IRC when I'm chatting in Arabic channels anyways.

bobfarrell8• 14 years ago

Hi, I don't have any knowledge of this kind of stuff so it would be very helpful if you could create an issue with some more info here: https://bitbucket.org/bobf/bpython/issues

At least then we know about the problem and can get around to fixing it. :)

glesica2• 14 years ago

I've been aware of this for awhile but this prompted me to play with it. Killer feature for me: it can be easily installed inside a virtualenv. This is not (last I checked) possible with ipython.

sambe• 14 years ago

I have had good experiences with ipython inside virtualenv, what's the problem?

glesica2• 14 years ago

Just that "pip install ipython" has never worked properly for me when I'm inside an virtuelenv. I just tried it and it worked, so maybe the problem was fixed in the year or two since I last tried it, or maybe I was broken but have been fixed in the last couple years...

k_bx4• 14 years ago

maybe the problem was that you need to do pip install -U ipython ?

leephillips• 14 years ago

This is really nice, but if you use vim you can use ScreenShell, which lets you execute parts of your buffer in a python interpreter (also works with lisp and any other language with a REPL). So you already have syntax coloring, completion, tags, etc.

jisaacstone• 14 years ago

using bpython has encouraged me to write more docstrings, which I previously did not do so much for personal projects ...

(because they are right there in the interpreter)

sho_hn2• 14 years ago

I love that the website has an "Alternatives" section linking to competitors. That's not only classy, it also communicates confidence and inspires trust.

Derbasti• 14 years ago

This is something I always loved about Python (as compared to other languages): There are several awesome interpreters available for it!

This one has a curses-based interactive GUI for docs and autocompletion.

IPython has this awesome qtconsole that can show matplotlib plots inline with the code. Then there is its HTML notebook which is probably awesome for presenting stuff.

Even IDLE is pretty cool, actually.

Is stuff like this available for other programming languages? I know Matlab has something vaguely similar to IPython and I think the IPython notebook is inspired by mathematica?

In comparison IRB seems really boring to me. Does Ruby have a cool interpreter? Perl? R?

masklinn2• 14 years ago

> Does Ruby have a cool interpreter?

I don't know if it's cool, but I know of at least one alternative to irb: http://pry.github.com/

jvoorhis• 14 years ago

Pry is pretty cool. It adds some debugger-like features and editor integration, adds some convenient built-in commands, and improves on the UI in similar ways to bpython.

emillon• 14 years ago

> There are several awesome interpreters available for it!

Technically, it's not another interpreter (like IronPython or Jython), just an interface to the classic CPython REPL.

draegtun• 14 years ago

> Does Ruby have a cool interpreter? Perl? R?

For Perl I use Devel::REPL (https://metacpan.org/module/Devel::REPL) but there are several others on CPAN (for eg: https://metacpan.org/module/Zoidberg) with varying levels of coolness.

disgruntledphd2• 14 years ago

for R, you're a fool (IMO) if you use anything but Emacs with Emacs Speaks Statistics.

spacemanaki• 14 years ago

Most Lisps will integrate with Emacs out of the box as an "inferior lisp process" which supports something I think is more valuable: send code straight from an editor buffer to an embedded REPL. This completely removes the copy-and-paste step you have when working with a regular, detached REPL. One of the more impressive uses of this is with ClojureScript, which integrates the compiler with a bit of JS running in a browser to allow you to send Cljs code straight from your editor to the browser.

You can use SLIME with Common Lisp and Clojure which is similar but adds a number of features like hints, docs, and debugging, although it was originally designed for CL so Clojure support is less powerful.

There are definitely Emacs modes like this for other languages, and probably similar plugins or whatever for other editors.

k_bx4• 14 years ago

Offtopic: with all these ipython/bpython's only thing that bugs me is need to do pip install -U ipython bpython (which downloads significant portion of bytes) in every virtualenv. I wonder if there's something like "pip install -U ipython --local-cache" option to copy existing ipython inside this virtualenv.

urschrei• 14 years ago

There is: http://stackoverflow.com/questions/4806448/how-do-i-install-...

k_bx4• 14 years ago

Wow, thanks a lot! I wonder why it's not in default somewhere.

gvalkov• 14 years ago

If you simply wish to access a virtualenv from your system ipython, you could do:

    with open('path/to/venv/bin/activate_this.py') as fh:
        exec(fh.read(), {'__file__' : fh.name})

Actually, having a %workon magic command for virtualenvwrapper[1] users seems like a useful thing. I think I'll write that ...

[1] http://pypi.python.org/pypi/virtualenvwrapper

DasIch2• 14 years ago

virtualenvwrapper has scripts that run after certain operations e.g. creating a virtualenv. I use this to install bpython, sphinx and tox into every new virtualenv.

vladev• 14 years ago

I've used bpython a lot in the past - mostly for it's instant syntax highlight and autocompletion, but I recently discovered ipython qtconsole and I can say it's much better (yes, it's not in the console, but I'm ok with that). Its syntax highlighting is as good as bpython's, but allows me to use it like a text editor and go up a few lines, edit, execute. Bpython cannot do that.

Also, bpython is a bit buggy when it comes to pasting about a page worth of code/string. In the nice case the syntax highlight gets confused. In the not so nice - it becomes completely unusable, so that I have to kill it.

k_bx4• 14 years ago

Yeah. And I use ipython's %ed command for that kind of long scripts (emacsclient as editor). Also really great feature.

cool-RR2• 14 years ago

What would make me use this is a way to get Django to use it when you launch `manage.py shell`, similarly to ipython.

One advantage over ipython I see here is that it doesn't use sqlite (I think), so it might run on Heroku.

cool-RR2• 14 years ago

Update: Django uses `bpython` by default if `ipython` isn't installed! Woohoo!

bobfarrell8• 14 years ago

Yeah, I don't use Django so I never did this myself, but somebody kindly did the work for us. :)

krob• 14 years ago

this is awesome.

mcnemesis• 14 years ago

just got me ipython (a ~few minutes back), and bpython (like a ~minute back), and this feels damn awesome! I mean bpython!

tripzilch• 14 years ago

Does BPython play nice with matplotlib/pylab yet? Last time I was very impressed with its functionality, but I could get it to draw a graph properly.

Fortunately, IPython, especially with the new --qtconsole, is also very very good.

Aissen• 14 years ago

I installed bpython, but found it to be much more CPU intensive than ipython, for working on small machines (like a raspberry pi). Of course it's not a problem if you have a reasonnably decent hardware.

Edit: setting auto_display_list to False in ~/.bpython/config (not XDG compliant directory :( ) helps a lot. You can then use completion only when you need it.

geirr• 14 years ago

I really like this: Add "import bpdb; bpdb.set_trace()" to your code, and from pdb type 'B' to drop into bpython.

krupan• 14 years ago

I'll switch to bpython when it gets all the readline shortcuts that I use without even thinking (like alt-b, alt-f, alt-backspace, ctrl-c, etc.).

bobfarrell8• 14 years ago

The worst thing is it's been at least two years since somebody first asked about this and we still haven't done it, even though it's really, really easy. :) I'll try to get this done soon if anybody is willing.

Bpython is a fancy interface to the Python interpreter

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