ruamel.yaml refuses to dump a scientific number

Question

I have a numpy array containing numbers written in scientific notation that I want to dump using ruamel.yaml. However, I get the following error message when I try to do it:

ruamel.yaml.representer.RepresenterError: cannot represent an object: 2.702069928616081e-06

I tried to convert it into a string using astype(str) from numpy but it does not fix the problem.

Answer 1

ruamel.yaml has no problem loading or dumping floats in scientific notation, neither using the C library nor in roundtrip mode:

import sys
import ruamel.yaml

yaml_str = """\
- 2.702069928616081e-06
"""

for typ in ['safe', 'rt']:
   yaml = ruamel.yaml.YAML(typ=typ)
   yaml.default_flow_style = False
   data = yaml.load(yaml_str)
   print('Python:', typ, type(data[0]))
   print(data)
   print('YAML:')
   yaml.dump(data, sys.stdout)

which gives:

Python: safe <class 'float'>
[2.702069928616081e-06]
YAML:
- 2.702069928616081e-06
Python: rt <class 'ruamel.yaml.scalarfloat.ScalarFloat'>
[2.702069928616081e-06]
YAML:
- 2.702069928616081e-06

Without your actual (minimal) program to reproduce this, there is no further indication on what you might be doing wrong.