Parsing YAML, return with line number

Here’s an improved version of puzzlet’s answer:

import yaml
from yaml.loader import SafeLoader

class SafeLineLoader(SafeLoader):
    def construct_mapping(self, node, deep=False):
        mapping = super(SafeLineLoader, self).construct_mapping(node, deep=deep)
        # Add 1 so line numbering starts at 1
        mapping['__line__'] = node.start_mark.line + 1
        return mapping

You can use it like this:

data = yaml.load(whatever, Loader=SafeLineLoader)