remake 0.6.3 documentation¶
Introduction¶
Remake is a smart Python build tool, similar to make. It is file based – all inputs and outputs of each task are files. It uses a pure-Python implementation to define a set of tasks, where any tasks can depend on the output from previous tasks. It makes it easy to define complex task graphs, using a filename formatter for each task to define its inputs and outputs. It is smart, in that if any of the tasks or any of the input files to a task’s content changes, those tasks will be rerun. Subsequent tasks will only be rerun if their input has changed.
Remake tracks the contents of each file and task, and can be used to generate a report of how any particular file was made. It is particularly suited to use in scientific settings, due to its ability to reliably recreate any set of output files, based on running only those tasks that are necessary.
Demonstration¶
Here is a simple remake file demo.py.
"""Simple remake file: in.txt -> fan_out1.txt -> out.txt
`> fan_out2.txt /
"""
from remake import Remake, TaskRule
# A remake file is defined by creating a Remake object.
demo = Remake()
class FanOut(TaskRule):
"""Takes one input file and uses two tasks to generate two output files"""
rule_inputs = {'in': 'data/in.txt'}
rule_outputs = {'fan_out_{i}': 'data/fan_out_{i}.txt'}
# This defines the output files, and the number of tasks this TaskRule will create.
var_matrix = {'i': [1, 2]}
def rule_run(self):
# self.inputs and self.outputs are dictionaries created from rule_inputs
# Each value is a pathlib.Path.
input_value = self.inputs['in'].read_text()
self.outputs[f'fan_out_{self.i}'].write_text(f'FanOut {self.i}: {input_value}')
class Out(TaskRule):
"""Takes the two output files produced by FanOut and combines them into one output file"""
rule_inputs = {f'fan_out_{i}': f'data/fan_out_{i}.txt'
for i in [1, 2]}
rule_outputs = {'out': 'data/out.txt'}
def rule_run(self):
input_values = []
for i in [1, 2]:
input_values.append(self.inputs[f'fan_out_{i}'].read_text())
self.outputs['out'].write_text(''.join(input_values))
This can be loaded in an interactive python shell using:
>>> from remake import load_remake
>>> demo = load_remake('demo.py').finalize()
>>> # Tasks are accessible using the classname of the TaskRule:
>>> demo.FanOut.tasks.status()
>>> demo.Out.tasks.status()
>>> # Or by using the demo object:
>>> demo.tasks.status()
>>> # All (remaining) tasks can be run:
>>> demo.run_all()
>>> # edit one of the tasks in demo.py, then reload it:
>>> demo = load_remake('demo.py').finalize()
Alternatively, remake can be used as a command line tool:
$ cat data/in.txt
input
$ remake run demo
=> demo <=
Status (complete/rescan/pending/remaining/cannot run): 0/1/0/3/0
Rescanning: /home/markmuetz/projects/remake/remake/examples/data/in.txt
1/3: 3491ba8fdd FanOut(i=1)
2/3: df3b4d6329 FanOut(i=2)
3/3: a20a6e7a29 Out()
Status (complete/rescan/pending/remaining/cannot run): 3/0/0/0/0
# edit FanOut.rule_run so that its output is different
$ remake run demo
=> demo <=
Status (complete/rescan/pending/remaining/cannot run): 0/0/2/1/0
1/3: 3491ba8fdd FanOut(i=1)
2/3: df3b4d6329 FanOut(i=2)
3/3: a20a6e7a29 Out()
Status (complete/rescan/pending/remaining/cannot run): 3/0/0/0/0
# edit Out.rule_run
$ remake run demo
=> demo <=
Status (complete/rescan/pending/remaining/cannot run): 2/0/1/0/0
3/3: a20a6e7a29 Out()
Status (complete/rescan/pending/remaining/cannot run): 3/0/0/0/0
$ cat data/out.txt
FanOut 1: input
FanOut 2: input
Contents: