Introduction

Quickstart

Install the package using pip:

pip install goeieDAG==0.0.2

Here are some examples of usage:

from pathlib import Path

import goeiedag
from goeiedag import ALL_INPUTS, INPUT, OUTPUT

workdir = Path("output")

graph = goeiedag.Graph()

# Extract OS name from /etc/os-release
graph.add(["grep", "^NAME=", INPUT, ">", OUTPUT],
        inputs=["/etc/os-release"],
        outputs=["os-name.txt"])
# Get username
graph.add(["whoami", ">", OUTPUT],
        inputs=[],
        outputs=["username.txt"])
# Glue together to produce output
graph.add(["cat", ALL_INPUTS, ">", OUTPUT.result],
        inputs=["os-name.txt", "username.txt"],
        outputs=dict(result="result.txt"))  # can also use a dictionary and refer to inputs/outputs by name

goeiedag.build_all(graph, workdir)

# Print output
print((workdir / "result.txt").read_text())

Using placeholders

Placeholders can be used at any position in the argument sequence. These are the supported placeholders:

INPUT: Substituted by the path to the input of the command. Invalid if multiple inputs were specified.
INPUT.name: Substituted by the input called name. Inputs must be specified as a dictionary.
ALL_INPUTS: Expands to all inputs, as separate arguments.
OUTPUT: Substituted by the path to the output of the command. Invalid if multiple outputs were specified.
OUTPUT.name: Substituted by the output called name. Outputs must be specified as a dictionary.
ALL_OUTPUTS: Expands to all outputs, as separate arguments.

Prefixing placeholders

Placeholders that refer to a single file (all except ALL_INPUTS/ALL_OUTPUTS) can also be combined with prefix strings, like this:

# Get username
graph.add(["whoami", ">" + OUTPUT],
        inputs=[],
        outputs=["username.txt"])