How do I generate yaml file via python code?

I need to generate a yaml file and want to use python to do that. This (How can I write data in YAML format in a file?) helped me a lot but I am missing a few more steps.

I want to have something like this in the end:

- A: a
  B:
    C: c
    D: d
    E: e

This:

d = {'- A':'a', 'B':{'C':'c', 'D':'d', 'E':'e'}}
with open('result.yml', 'w') as yaml_file:
    yaml.dump(d, yaml_file, default_flow_style=False)

gives me this:

'- A': a
B:
  C: 'c'
  D: 'd'
  E: 'e'

I have a couple problems here.

1. I need the dash before A, but in this way – A is in ” , next rows are not
2. Indention is wrong. B, C, D and E need to go one indent to the right (if the ‘ in front of A goes away…) B needs to start right under A

For another step I would need some more, finally I want do have:

steps
- A: a
  B:
    C: c
    D: d
    E: e
- A: a1
  B:
    C: c1
    D: d1
    E: e1
- A: a2
  B:
    C: c2
    D: d2
    E: e2
....

Can someone help?

>Solution :

- A: designates a list, and that list contains a dict. So what you need, is a list:

d = [{'A':'a', 'B':{'C':'c', 'D':'d', 'E':'e'}}]
with open('result.yml', 'w') as yaml_file:
    yaml.dump(d, yaml_file, default_flow_style=False)