mario 0.0.136

Shell pipes for Python.

Your favorite plumbing snake 🐍🔧 with your favorite pipes, right in your shell 🐢.

Installation

Mario

Get Mario with pip:

python3.7 -m pip install mario

If you’re not inside a virtualenv, you might get a PermissionsError. In that case, try using:

python3.7 -m pip install --user mario

or for more isolation, use pipx:

pipx install --python python3.7 mario

Mario addons

The mario-addons package provides a number of useful commands not found in the base collection.

Get Mario addons with pip:

python3.7 -m pip install mario-addons

If you’re not inside a virtualenv, you might get a PermissionsError. In that case, try using:

python3.7 -m pip install --user mario-addons

or for more isolation, use pipx:

pipx install --python python3.7 mario
pipx inject mario mario-addons

Usage

Basics

Invoke with mario at the command line.

$ mario eval 1+1
2

Use map to act on each item in the file with python commands:

$ mario map 'x.upper()' <<<'abc'
ABC

Chain python functions together with !:

$ mario map 'x.upper() ! len(x)' <<<hello
5

or by adding another command

$ mario map 'x.upper()' map 'len(x)' <<<hello
5

Use x as a placeholder for the input at each stage:

$ mario map ' x.split()[0] ! x.upper() + "!"' <<<'Hello world'
HELLO!

$ mario map 'x.split()[0] ! x.upper() + "!" ! x.replace("H", "J")' <<<'Hello world'
JELLO!

Automatically import modules you need:

$ mario map 'collections.Counter ! dict' <<<mississippi
{'m': 1, 'i': 4, 's': 4, 'p': 2}

You don’t need to explicitly call the function with some_function(x); just use the function’s name some_function. For example, instead of

$ mario map 'len(x)' <<<'a\nbb'
5

try

$ mario map len <<<'a\nbb'
5

More commands

Here are a few commands. See Command reference for the complete set.

eval

Use eval to evaluate a Python expression.

$ mario eval 'datetime.datetime.utcnow()'
2019-01-01 01:23:45.562736

map

Use map to act on each input item.

$ mario map 'x * 2' <<<'a\nbb\n'
aa
bbbb

filter

Use filter to evaluate a condition on each line of input and exclude false values.

$  mario filter 'len(x) > 1' <<<'a\nbb\nccc\n'
bb
ccc

apply

Use apply to act on the sequence of items.

$ mario apply 'len(x)' <<<$'a\nbb'
2

reduce

Use reduce to evaluate a function of two arguments successively over a sequence, like functools.reduce.

For example, to multiply all the values together, first convert each value to int with map, then use reduce to successively multiply each item with the product.

$ mario map int reduce operator.mul <<EOF
1
2
3
4
EOF

24

chain

Use chain to flatten an iterable of iterables of items into an iterable of items, like itertools.chain.from_iterable.

For example, after calculating a several rows of items,

$ mario  map 'x*2 ! [x[i:i+2] for i in range(len(x))]'   <<EOF
ab
ce
EOF
['ab', 'ba', 'ab', 'b']
['ce', 'ec', 'ce', 'e']

use chain to put each item on its own row:

$ mario  map 'x*2 ! [x[i:i+2] for i in range(len(x))]' chain  <<EOF
ab
ce
EOF
ab
ba
ab
b
ce
ec
ce
e

Then subsequent commands will act on these new rows. Here we get the length of each row.

$ mario  map 'x*2 ! [x[i:i+2] for i in range(len(x))]' chain map len <<EOF
ab
ce
EOF
2
2
2
1
2
2
2
1

async-map

Making sequential requests is slow. These requests take 20 seconds to complete.

% time mario map 'requests.get ! x.text ! len' apply max <<EOF
http://httpbin.org/delay/5
http://httpbin.org/delay/1
http://httpbin.org/delay/4
http://httpbin.org/delay/3
http://httpbin.org/delay/4
EOF

302

0.61s user
0.06s system
19.612 total

Concurrent requests can go much faster. The same requests now take only 6 seconds. Use async-map, or async-filter, or reduce with await some_async_function to get concurrency out of the box.

% time mario async-map 'await asks.get ! x.text ! len' apply max <<EOF
http://httpbin.org/delay/5
http://httpbin.org/delay/1
http://httpbin.org/delay/4
http://httpbin.org/delay/3
http://httpbin.org/delay/4
EOF

297

0.57s user
0.08s system
5.897 total

Configuration

Define new commands and set default options. See Configuration reference for details.

Plugins

Add new commands like map and reduce by installing Mario plugins. You can try them out without installing by adding them to any .py file in your ~/.config/mario/modules/.

Share popular commands by installing the mario-addons package.

Q & A

What’s the status of this package?

• This package is experimental and is subject to change without notice.

• Check the issues page for open tickets.

Why another package?

A number of cool projects have pioneered in the Python-in-shell space. I wrote Mario because I didn’t know these existed at the time, but now Mario has a bunch of features the others don’t (user configuration, multi-stage pipelines, async, plugins, etc).

• https://github.com/Russell91/pythonpy

• http://gfxmonk.net/dist/doc/piep/

• https://spy.readthedocs.io/en/latest/intro.html

• https://github.com/ksamuel/Pyped

• https://github.com/ircflagship2/pype