stitch

stitch is a library for making reproducible reports. It takes a markdown source file, executes the code chunks, captures the output, and stitches the output into the destination file.

Those familiar with knitr and RMarkdown will recognize it as a python clone of those great libraries. It’s also heavily influenced by knitpy.

While stitch is written in python, it can be used for any of the dozens of Jupyter kernels.

Examples

See the example site for a side-by-side comparison of the markdown source and rendered output. Links to a more complicated document rendered in various formats is also provided.

Install

At the moment, the name stitch is taken on PyPI via an inactive project. You can install stitch from PyPI via

pip install knotr

I know, it’s confusing. I’ve filed a claim for stitch on PyPI, but I think the people working that support queue are over-worked. Once that gets processed, I’ll put it up on conda-forge as well. If you need a mnemonic, it’s “I want knitr, but not the one written in R. Also I wanted to confuse R users. And knots are kind of like a buggy version of knits.

But to be clear the package name and command-line tool is stitch.

You’ll also need to have a recent version of pandoc. Either use your system package manager, or use the pypandoc provided on conda-forge, which includes pandoc.

Usage

You write a markdown file, and include code chunks that look like

```{kernel_name, [chunk_name], **kwds}
# your code here
```

The kernel_name is required (see jupyter kernelspec list). The chunk_name is optional; it controls things like the name assigned to plots if they’re saved to disk.

The supported keyword arguments are

  • eval: bool, whether to execute the code chunk
  • echo: bool, whether to include the input code chunk in the output

More options will be added.

The command-line interface is essentailly the same as pandocs. For the most part you call

stitch input_file.md -o output_file.html

You can use -t for the output type, or infer it from the file extension of -op. All other options are passed through to pandoc.

stitch defines a few new options that control stitch-specific features

  • --no-standalone
  • --no-self-contained

What’s in a Name?

The name stitch has a couple meanings. Like R’s knit, we are taking a source document, executing code chunks, and kniting or stitching the output back into the document.

The second meaning is for stitch bringing together a bunch of great libraries, minimizing the work we have to do ourselves. stitch uses

  • Pandoc markdown parsing and conversion to the destination output
  • jupyter, specifically jupyter-client for managing kernels, passing code to kernels, and capturing the output
  • pandocfilters for converting code-chunk output to pandoc’s AST
  • pypandoc for communicating with pandoc
  • click for the command-line interface.

stitch itself is fairly minimal. The main tasks are

  • processing code-chunk arguments
  • passing the correct outputs from the jupyter kernel to pandocfilters
  • assembling all the chunks of text, code, and output in a sensible way
  • making things look nice

Contents:

Indices and tables