Ticket #91 (reopened enhancement)

Opened 6 years ago

Last modified 2 days ago

emit no anchors and aliases

Reported by: Andrey Owned by: xi
Priority: normal Component: pyyaml
Severity: normal Keywords:
Cc: w@…


Hi, is it possible to avoid using anchors and aliases? So to output

[1, 1]


- 1
- 1

and not as

- &id1 1
- *id1


Change History

comment:1 Changed 6 years ago by xi

  • Status changed from new to closed
  • Resolution set to worksforme

It works for me:

>>> import yaml
>>> print yaml.dump([1,1], default_flow_style=False)
- 1
- 1

Could you post a code snippet that produces the output with aliases?

comment:2 Changed 4 years ago by iand@…

  • Status changed from closed to reopened
  • Resolution worksforme deleted

I can reproduce this with the following input, regardless of flow style. Having the option to disable anchors & aliases would be extremely handy for me.

import yaml print yaml.dump([1L, 1L])

comment:3 Changed 3 years ago by anonymous

+1 - yaml loses a lot of usefulness when it isn't human readable, and having hundreds of aliases in a document with names like id001 is hard for me to parse.

comment:4 Changed 2 years ago by w@…

  • Cc w@… added

This is actually really easy, it's just not documented:

class CustomDumper?(SafeDumper?):

A custom YAML dumper that never emits aliases"

def ignore_aliases(self, _data):

return True

Can this please be documented?

comment:5 Changed 2 years ago by anonymous

Here is a quick script to remove anchors and aliases:


"""Parse and re-emit YAML without aliases.

import argparse
import sys
import yaml

def main():
    parser = argparse.ArgumentParser()
        'file', nargs='?', default='-', type=argparse.FileType('r'))
    args = parser.parse_args()

    Loader = yaml.SafeLoader
    Dumper = yaml.SafeDumper

    Dumper.ignore_aliases = lambda self, data: True
    yaml.dump(yaml.load(args.file, Loader=Loader), sys.stdout, Dumper=Dumper)

if __name__ == '__main__':

Save as ~/bin/yaml-rewrite

I use it as a git diff filter. Register with

git config --global diff.cleanyaml.textconv yaml-rewrite

and in .gitattributes:

*.yaml diff=cleanyaml

comment:6 Changed 2 days ago by maskodok <galihadiputro87@…>

The only thing more I could hope for is documentation of all these features (other than reading through the code).  Cipto Junaedy Is this in process? Can I help? About  Unit Link Terbaik di Indonesia Commonwealth Life Investra Link


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