/ Command-line Tools

Powerful Python pipelines for your shell

Powerful Python pipelines for your shell

Mario: Shell pipes in Python

Have you ever wanted to use Python functions directly in your Unix shell? Mario can read and write csv, json, and yaml; traverse trees, and even do xpath queries. Plus, it supports async commands right out of the box. Build your own commands with a simple configuration file, and install plugins for even more!

Mario is the plumbing snake 🐍🔧 helping you build data pipelines in your shell 🐢.

Features

  • Execute Python code in your shell.
  • Pass Python objects through multi-stage pipelines.
  • Read and write csv, json, yaml, toml, xml.
  • Run async functions natively.
  • Define your own commands in a simple configuration file or by writing Python code.
  • Install plugins to get more commands.
  • Enjoy high test coverage, continuous integration, and nightly releases.

Installation

Mario

Windows support is hopefully coming soon. Linux and MacOS are supported now.

Get Mario with pip:

.. code-block:: bash

python3.7 -m pip install mario

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

.. code-block:: bash

python3.7 -m pip install --user mario

or for more isolation, use pipx <https://github.com/pipxproject/pipx/>_:

.. code-block:: bash

 pipx install --python python3.7 mario

Mario addons

The mario-addons <https://mario-addons.readthedocs.io/>__ package provides a number of useful commands not found in the base collection.

Get Mario addons with pip:

.. code-block:: bash

python3.7 -m pip install mario-addons

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

.. code-block:: bash

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

or for more isolation, use pipx <https://github.com/pipxproject/pipx/>_:

.. code-block:: bash

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

..
installation-inclusion-end

Quickstart

Basics

Invoke with mario at the command line.

.. code-block:: bash

$ mario eval 1+1
2

Given a csv like this:

.. code-block:: bash

$ cat <<EOF > hackers.csv
name,age
Alice,21
Bob,22
Carol,23
EOF

Use read-csv-dicts to read each row into a dict:

.. code-block:: bash

$ mario read-csv-dicts < hackers.csv
{'name': 'Alice', 'age': '21'}
{'name': 'Bob', 'age': '22'}
{'name': 'Carol', 'age': '23'}

Use map to act on each input item x :

.. code-block:: bash

$ mario read-csv-dicts map 'x["name"]' < hackers.csv
Alice
Bob
Carol

Chain Python functions together with !:

.. code-block:: bash

$ mario read-csv-dicts map 'x["name"] ! len' < hackers.csv
5
3
5

or by adding another command

.. code-block:: bash

$ mario read-csv-dicts map 'x["name"]' map len < hackers.csv
5
3
5

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

.. code-block:: bash

$ mario read-csv-dicts map 'x["age"] ! int ! x*2'  < hackers.csv
42
44
46

Automatically import modules you need:

.. code-block:: bash

$ 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

.. code-block:: bash

$ mario map 'len(x)' <<EOF
a
bb
EOF
1
2

try

.. code-block:: bash

$ mario map len <<EOF
a
bb
EOF
1
2

More commands

Here are a few commands. See Command reference <https://python-mario.readthedocs.io/en/latest/cli_reference.html>_ for the complete set, and get even more from mario-addons <https://mario-addons.readthedocs.org/>__.

eval

Use eval to evaluate a Python expression.

.. code-block:: bash

% mario eval 'datetime.datetime.utcnow()'

2019-01-01 01:23:45.562736

map

Use map to act on each input item.

.. code-block:: bash

$ mario map 'x * 2' <<EOF
a
bb
EOF
aa
bbbb

filter

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

.. code-block:: bash

$ mario filter 'len(x) > 1' <<EOF
a
bb
ccc
EOF
bb
ccc

apply

Use apply to act on the sequence of items.

.. code-block:: bash

$ mario apply 'len(x)' <<EOF
a
bb
EOF
2

chain

Use chain to flatten a list of lists into a single list, like itertools.chain.from_iterable <https://docs.python.org/3/library/itertools.html#itertools.chain.from_iterable>_.

For example, after generating a several rows of items,

.. code-block:: bash

$ mario read-csv-tuples <<EOF
a,b,c
d,e,f
g,h,i
EOF
('a', 'b', 'c')
('d', 'e', 'f')
('g', 'h', 'i')

use chain to put each item on its own row:

.. code-block:: bash

$ mario read-csv-tuples chain <<EOF
a,b,c
d,e,f
g,h,i
EOF
a
b
c
d
e
f
g
h
i

async-map

..
async-inclusion-start

Making sequential requests is slow. These requests take 16 seconds to complete.

.. code-block:: bash

   % time mario map 'await asks.get ! x.json()["url"]'  <<EOF
   http://httpbin.org/delay/5
   http://httpbin.org/delay/1
   http://httpbin.org/delay/2
   http://httpbin.org/delay/3
   http://httpbin.org/delay/4
   EOF
   https://httpbin.org/delay/5
   https://httpbin.org/delay/1
   https://httpbin.org/delay/2
   https://httpbin.org/delay/3
   https://httpbin.org/delay/4
   0.51s user
   0.02s system
   16.460 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.

.. code-block:: bash

   % time mario async-map 'await asks.get ! x.json()["url"]'  <<EOF
   http://httpbin.org/delay/5
   http://httpbin.org/delay/1
   http://httpbin.org/delay/2
   http://httpbin.org/delay/3
   http://httpbin.org/delay/4
   EOF
   https://httpbin.org/delay/5
   https://httpbin.org/delay/1
   https://httpbin.org/delay/2
   https://httpbin.org/delay/3
   https://httpbin.org/delay/4
   0.49s user
   0.03s system
   5.720 total

..
async-inclusion-end

.. _config-intro:

Configuration

Define new commands and set default options. See Configuration reference <config_reference.html>_ 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 <https://mario-addons.readthedocs.io/en/latest/readme.html>_ package.

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