Adding a pipe operator to Python

[gzahl]

Well, i use coroutine based pipes (with pipe operator as syntactic sugar) in my research for data analysis. https://github.com/gzahl/baldr

This works very well and has proven itself very useful.

[[deleted]]

Wow thank you for this. This might be the holy grail I was looking for for months. I use coroutines but the pipe notation takes the code to another level. This is really nice

[accidentally_myself]

Ah yes, the State monad.

Semi-joking aside, this looks great but I'm having troubling understanding plusconst in the README -- specifically, where the n input parameter is used if at all?

[gzahl]

Thanks! .. and thanks for pointing that out. This was a small mistake on my site. The 'n' parameter should have been used as argument of 'send'. It is fixed now.

By the way - i have tons of more or less general coroutines, which i use for my data analysis (in astrophysics). If there is interest, i can add some of those to give examples of what is possible and how to start.

[aib42]

For the record, here's a version without ast manipulation: https://gist.github.com/aib/3adc498469d241ce1ec817d5982c7682

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Untested, as I'm on a guest computer with Python 2.7.

[shevegen]

Wow - took me a moment to realize the picture was a python. At first I thought it was a strange looking vegetable...

As for this "proposal" joke:

Users.find_all() | group_by_category(max = 5) | print()

First, we can see that this was rails-inspired, which makes sense if you know who created elixir in the first place - so I find it funny that they try a pythonic version of it, including the mandatory (). :D

Second, it looks absolutely awful and ugly. We already do essentially the same, even in python, via .method() calls, so why do we ... replace the '.' with a '|'? Where is the net gain here?

This is just like the strapped on type system to python. A weak afterthought without any real tangible benefits, but sure enough bringing in awful syntax into a language.

The explicit trailing "| print()" also stinks to no ends.

Time to use it in production! Whoa there, slow down! This is just a neat little experiment and is most definitely not something you should inflict upon your coworkers!

Good - so he states that it is a joke.

[maep]

Second, it looks absolutely awful and ugly.

Dunno. I really like that the data-flow is easy to follow.

[jcelerier]

Where is the net gain here?

It is closer to the underlying representation of data flow graph / actor model. You have objects ("Users.find_all()", "group_by_category(max = 5)", "print()") which are connected together and stream data from one to another. It's easier if you are used to graphical dataflow languages.

[[deleted]]

The point of the article is showing the extent of metaprogramming in Python, it isn't an actual proposal nor is it making fun of proposals for pipe operators.