in

add input arguments to step context

in sets the input arguments for a step. pypyr adds anything in in to the context so that the decorated step can use these key-value pairs.

in is a mapping, also known as a dict {}. You can use complex, nested structures. pypyr will honor the data types of the yaml values you set in your pipeline.

# arbitrarily complex nested input args, 
# with different data types, 
# just to make a point.
in:
  key1: value 1
  key2: 
    - list item 1
    - 2.2: dict inside a list
      2.3: [1, 2, 3]
  key3: 456
  key4: True
  key5:
    nestedDictKey: nested map value
    anotherKey: another value

in evaluates once at the beginning of step execution, BEFORE the foreach and while decorators. It does not re-evaluate for each loop iteration.

scope

in is only in scope for the duration of the step it decorates. Context properties that you set here in in do not endure after the step completes.

If you want to set context properties that exist beyond the current step, use one of the context steps, such as

• pypyr.steps.set
• pypyr.steps.contextcopy
• pypyr.steps.default

set context parameters in preceding steps

Although in is handy to set input parameters for a specific step, you can also prepare context parameters beforehand in a previous step using one of the context setting built-in steps. You can prepare your step’s context key(s) as many steps previous as you like in this way, and there can be other steps in between too, as long no step in between resets or overwrites that particular context key.

# ./context-and-in.yaml
steps:
  - name: pypyr.steps.set
    comment: set echoMe for the following step here
    in:
      set:
        echoMe: arbitrary value here
  - pypyr.steps.echo # echo echoMe, set in previous step
  - name: pypyr.steps.set
    comment: newKey will stay in context after this step
    in:
      arb: arb substitution value
      set:
        newKey: 'XXX {arb} YYY'
  - name: pypyr.steps.contextcopy
    comment: copy newKey to echoMe
    in:
      contextCopy:
        echoMe: newKey
  - pypyr.steps.echo # output echoMe, set in previous step

This pipeline will result in:

$ pypyr context-and-in
arbitrary value here
XXX arb substitution value YYY