How to import variables from a Python file?

Questions
1

Say I have a file foo.py with the following contents:

a = 1
b = 2
c = 'xyz'

Is there a way to “import” these variables in my document dynamically? I’d like to avoid going through json or another intermediate format if possible.

2

If the source file is so simple you could parse it as TOML data:

#toml("a.py")

or write your own parser:

#let load-vars(file) = {
  let source = read(file)
  let vars = (:)
  for line in source.split("\n") {
    let assignment = line.match(regex("^\s*(.*?)\s*=\s*(.*?)\s*$"))
    if assignment != none {
      vars.insert(..assignment.captures)
    }
  }
  return vars
}

#load-vars("a.py")

For more complex cases the pyrunner package might do the job:

#import "@preview/pyrunner:0.2.0" as py

// Equivalent to #let source = read("a.py")
#let source = ```
a = 1
b = 2
c = 'xyz'
```.text

#py.block(source + "\na")

#py.block(source + "\nb")

#py.block(source + "\nc")

but see the package documentation for limitations (in particular you can’t run Python code that uses third-party packages).

2 Likes
3

This is more Python than Typst, but the following can give you all the variables from the current module, which may be useful:

{k: v for k, v in globals().items() if not k.startswith('__')}

applied to your example, you’ll get

{'a': 1, 'b': 2, 'c': 'xyz'}

I think the easiest way from there would still be converting that to JSON (or another Typst readable format), but there are probably other paths open as well.