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Examples
========
Basic round trip of parsing YAML to Python objects, modifying
and generating YAML::
from __future__ import print_function
import ruamel.yaml
inp = """\
# example
name:
# details
family: Smith # very common
given: Alice # one of the siblings
"""
code = ruamel.yaml.load(inp, ruamel.yaml.RoundTripLoader)
code['name']['given'] = 'Bob'
print(ruamel.yaml.dump(code, Dumper=ruamel.yaml.RoundTripDumper), end='')
.. example code small.py
Resulting in ::
# example
name:
# details
family: Smith # very common
given: Bob # one of the siblings
.. example output small.py
----
YAML handcrafted anchors and references as well as key merging
are preserved. The merged keys can transparently be accessed
using ``[]`` and ``.get()``::
import ruamel.yaml
inp = """\
- &CENTER {x: 1, y: 2}
- &LEFT {x: 0, y: 2}
- &BIG {r: 10}
- &SMALL {r: 1}
# All the following maps are equal:
# Explicit keys
- x: 1
y: 2
r: 10
label: center/big
# Merge one map
- <<: *CENTER
r: 10
label: center/big
# Merge multiple maps
- <<: [*CENTER, *BIG]
label: center/big
# Override
- <<: [*BIG, *LEFT, *SMALL]
x: 1
label: center/big
"""
data = ruamel.yaml.load(inp, ruamel.yaml.RoundTripLoader)
assert data[7]['y'] == 2
.. example code anchor_merge.py
----
The ``CommentedMap``, which is the ``dict`` like construct one gets when round-trip loading,
supports insertion of a key into a particular position, while optionally adding a comment::
yaml_str = """\
first_name: Art
occupation: Architect # This is an occupation comment
about: Art Vandelay is a fictional character that George invents...
"""
data = ruamel.yaml.round_trip_load(yaml_str)
data.insert(1, 'last name', 'Vandelay', comment="new key")
print(ruamel.yaml.round_trip_dump(data))
gives::
first_name: Art
last name: Vandelay # new key
occupation: Architect # This is an occupation comment
about: Art Vandelay is a fictional character that George invents...
Please note that the comment is aligned with that of its neighbour (if available).
The above was inspired by a `question <http://stackoverflow.com/a/36970608/1307905>`_
posted by *demux* on StackOverflow.
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