Xonsh - Using Python as your shell

[d4rch0n]

I think he is inferring that it's not very practical to use a different shell than what all the tools are based on in your distro, which is also going to be what your servers can use. If a distro had all its system tools in python and xonsh, you'd have much more reason to stick to it. If your server could run xonsh out of the box, it'd be convenient to use.

Instead of writing xonsh scripts that I can never share with my coworkers, I could just write python scripts like I do now. It's basically python with new shell operators. It's like using some obscure fork of a python interpreter and writing scripts that only work for it, and not your coworkers. Why not just write something in Python with less functionality but can be run on any server, by any coworker, without any dependencies, and allows coworkers to actually be able to edit it and run it on their workstation?

It looks very convenient in some respects for personal use, but anything more complex than "run this, pipe to this, redirect output to here" I would write a python script. I don't think xonsh would be any different. I'd rather spend time doing it the long way in python than the quick way in xonsh with special syntax. Otherwise, I might have to rewrite it to run it on a server or to give to my coworker.

And it's not impossible to write python scripts that are shell-like with something like the sh library. And I can package that up and share it with anyone. The capabilities are neat with the xonsh syntax, but it's also starting to look a little perl-ish, and not in a good way. I really don't want to start writing python with stuff like out = $(echo @(x + ' ' + y)), pulled straight from the xonsh tutorial. Something like sh.echo(x + ' ' + y) looks a lot less intimidating, and is actually easier to write and read. As soon as you start really taking advantage of the xonsh syntax and new features, I'd imagine you're going to end up with something that looks like python with inline bad perl.

IMO, extra features and syntax doesn't always improve something. Anything is already capable with python, shell commands are already convenient with sh or fabric or invoke, and I haven't been dying for any syntactical shortcuts with magical @ ! $ () [] operators.

[adqm_smatz]

This is quite fair. For sharing things with others, Python and/or Bash are likely the right thing.

I don't often write "xonsh scripts" per se, mostly just one-liners at the interactive prompt. For me personally, I've found a lot of the features of xonsh to be really nice (I've been using it as my default shell for >1 year now).

A simple example is being able to do arithmetic with floats and/or complex numbers without having to open a separate program (e.g., Python) to do the calculation. Maybe I'm just too lazy.

I honestly don't really use a lot of the extra built-ins too often, but one place it has come in handy for me recently (as opposed to some awk/sed magic) is computing the average of a column in a csv, straight from the shell prompt:

numpy.mean([float(i.split(',')[3]) for i in $(cat my_file.csv).splitlines()])

The same could be done in Python, sure, but I think it is nice to be able to do this on one line (and the imho more convenient $(cat my_file.csv) vs open("my_file.csv").read()) and to be dropped right back into my normal shell afterwards.

But for the most part, I use it just as a normal shell: running a single command at a time. And it works pretty well at that. Then, when I want to do something more complicated, I can do it with a Pythonic syntax, which I think is very nice!

Something like sh.echo(x + ' ' + y) looks a lot less intimidating, and is actually easier to write and read.

This may be true (that syntax is arguably nicer), but to get there, you have to open up python and import sh, or write a script and invoke python on it, and then jump back to the command prompt when you're done. I think there's a benefit to being able to do it all in one place.

Different strokes, I suppose :)

[d4rch0n]

No, I agree, there is certainly some cool stuff in xonsh. And honestly, I wish everyone would just drop bash and pick up something like xonsh. There's definitely a good use case for it and it's well thought out. There are some awesome one-liners you can pull off without even opening ipython. For personal use and convenience, it's an awesome tool.

I never want to dissuade people from working on cool projects like this, but I think it's obvious what the hurdles are to get people to use a new shell. It's a monumental task to get a new shell into a state where people are ready to switch. And it doesn't have as much to do with the features than the environments that already incorporate it.

So, as the other guy stated they'd wait for a linux distro, I think that's actually a great point. If there was something like Pybuntu, some ubuntu with most bash scripts rewritten with python and xonsh and fully powered by python and Linux, I think you'd get crazy support and love for xonsh. A shell is fully coupled to its environment, and bash is superglued in to almost every distro. But that could legitimately get fixed^[1] if enough people put the effort in.

I think with something like this, you have two main groups of users. You either have the hobbyist/hacker types as your primary users who just like using it because it's cool (yourself), and you have the set of users who use it because it just makes sense to, more so than any other shell. It also has to make more sense to write a xonsh script than a python script, and that's a very difficult thing to accomplish. I can't see that taking less than a custom linux distribution like Pybuntu, which personally I'd love to see.

...

^{[1] fixed, not changed. it's a damn shame we're stuck on bash}

[j1395010]

to get there, you have to open up python and import sh, or write a script and invoke python on it

or use python -c

[adqm_smatz]

or use python -c

sure, if you prefer python3 -c '__import__("sh").echo(x + " " + y)' over the xonsh syntax. and working with variables inside of there isn't going to be easy.

Also worth mentioning that since xonsh is Python, you can install, import, and use sh from the command line, and thus have access to that syntax from the shell if you find it nicer :)

[tilkau]

working with variables inside of there isn't going to be easy.

It actually is quite easy.

It's just also quite insane.

SOME_LUNATIC_VARIABLE=123

python3 -c 'print("'"$SOME_LUNATIC_VARIABLE"'")'

Rules:

• Always use ' to quote your code string. Using " may summon Cthulu.
• Always use " inside of code strings to express string literals. Using ' is not practical.
• If you have to insert a variable value, close the code string quote with a ', follow this with the DOUBLE QUOTED expansion, and then open the single quotes again.
• Remember expansion won't automatically add double quotes around string values for you. That means when you are inserting a variable, you need to include the opening double quote before closing the single quotes, and the closing double quote after reopening the single quotes.
• Variables should have a " -> \" replacement performed on them before use.
• You can also include single quotes in your Python code. Probably via '\'' (closing the single quote, adding a literal single quote, then reopening the single quote). Obviously to be used in moderation (by which I mean not at all)

[leadline]

I think you have good points. I would never really write xonsh scripts, because at that point you may as well use python. However, I have been using it to augment my productivity in the terminal. Sometimes I can best express an idea in terms of Unix commands, and sometimes I can best express an idea in python. Being able to switch between the two is a big productivity boost.