如何使用带前导零的 int 转储 YAML？

Question

I need to dump an integer with leading zeros, but not as a string. I can dump it like a string in this way:

import sys
from ruamel.yaml import YAML

data = {'identifier': '001'}

yaml = YAML()
yaml.dump(data, sys.stdout)

The result is:

identifier: '001'

I do not need to dump as a string, but as a number.
I need a result like:

identifier: 001

How can I do it?

Answer 1

First thing to do if you need to check if a particular output can be generated is trying to round-trip the result:

import sys
import ruamel.yaml

yaml_str = """\
identifier: 001
"""
    
yaml = ruamel.yaml.YAML()
data = yaml.load(yaml_str)
data['another'] = double_o_one = data['identifier']
yaml.dump(data, sys.stdout)

which gives:

identifier: 001
another: 001

So this proves this can be done programmatically, and if worst comes to worst and you cannot figure out how to make the double_o_one from scratch, you can load it from a string.

If you investigate a bit more and have a look at the source of scalarint.py :

print(type(double_o_one))
print(double_o_one.__dict__)
print()

data['james'] = double_o_seven = ruamel.yaml.scalarint.ScalarInt(7, width=3)
yaml.dump(data, sys.stdout)

and that gives:

<class 'ruamel.yaml.scalarint.ScalarInt'>
{'_width': 3, '_underscore': None}

identifier: 001
another: 001
james: 007

So if you start out with a string x = '001' , you do x = ScalarInt(int(x), len(x))

Answer 2

>>> data = {'identifier': 0o001}

This will convert to an integer. But , not in the format you specified.