StepInfo objects

Note

This feature was introduced in StepUp 1.3.0.

The step() function always return an instance of StepInfo. This object holds arguments used to define the step, which may be useful for creating follow-up steps. All API functions that create a step by calling the step() function also return the StepInfo object.

Especially for higher-level API functions that create more advanced steps, such as the ones in StepUp RepRep, it can be convenient to access the paths constructed inside the API function instead of reconstructing them manually in your plan.py script.

The StepInfo object has inp, env, out and vol attributes, corresponding to the arguments passed into the step() function. The main difference to the arguments passed in, is that environment variables are substituted in the paths.

In addition, StepInfo has three methods: filter_inp(), filter_out() and filter_vol(), which can be used to get a subset of paths. These functions take the same arguments as those of the glob() function and also return an NGlobMulti instance.

Note that the StepInfo object will only contain information known at the time the step is defined. Amended information (inputs, outputs, …) cannot be retrieved from StepInfo objects. Also note that relative paths in inp, out and vol are relative to the working directory.

Example

Let’s assume you are using a library with an API function create_fancy_pdf, which takes a source directory as input and outputs a PDF file. (This is a hypothetical example for illustrative purposes.) You can find the full list of inputs and the output as follows:

from stepup.core.api import static, copy
from stepup.fancy.api import create_fancy_pdf  # hypothetical API function

# Plan the creation of the fancy PDF
static("source/")
glob("source/**", _defer=True)
info = create_fancy_pdf("source/")

# Copy files related to the fancy PDF, e.g. to publish them or back up files.
mkdir("../public")
copy(info.filter_out("*.pdf").single, "../public/")
mkdir("../backup")
for path_inp in info.inp:
    copy(path_inp, "../backup")