import io

import sys

import ruamel.yaml

from ruamel.yaml import YAML

ruamel_yaml = YAML(typ="rt")

ruamel_yaml.default_flow_style = False

ruamel_yaml.preserve_quotes = True

ruamel_yaml.width = 1024

buf = """\

# top level

top:

  # next level 1

  - { here: 1, there: 2 }

  # next level 2

  - { there: 1, here: 2 }

top2:

  # next level 1-2

  - { here: 11, there: 22 }

  # next level 2-2

  - { there: 11, here: 22 }

"""

if len(sys.argv) > 1:

    buf = open(sys.argv[1]).read()

ruamel_data = ruamel_yaml.load(buf)

ruamel_yaml.indent(mapping=2, sequence=4, offset=2)

outf = io.StringIO()

ruamel_yaml.dump(ruamel_data, outf)

buf = outf.getvalue()

print(buf)

ruamel_data = ruamel_yaml.load(buf)

outf = io.StringIO()

ruamel_yaml.dump(ruamel_data, outf)

buf = outf.getvalue()

print(buf)