Capture Return Value from exec

Question

yaml file:

$ cat ec2_attr.yml

treeroot:
    branch1:
        name: Node 1
        snap: |
          def foo():

              from         


        

Answer 1

You can use exec like this:

import yaml
import pprint

with open('./a.yaml') as fh:
    try:
        yaml_dict = yaml.load(fh)
    except Exception as e:
        print(e)
    else:
      a = {}
      exec(yaml_dict['treeroot']['branch1']['snap'], {}, a)
      print('The Value is: %s' % (a['foo']()))

And change your YAML to this:

treeroot:
  branch1:
      name: Node 1
      snap: |
        def foo():
            return("test")

  branch2:
      name: Node 2

Actually, You can use exec(str, globals, locals)

• globals()
• locals()

The built-in functions globals() and locals() return the current global and local dictionary, respectively, which may be useful to pass around for use as the second and third argument to exec().

Also, You can read The exec Statement and A Python Mystery and locals and globals