When inspecting keyword parameters in a function call, the keyword is stored as a string and not as a AST node:

>>> import ast
>>> r = "f(a,   xxxxxxxxxxa  =  34, y=23)"
>>> node = ast.parse(r)
>>> ll = node.body[0].value.keywords[0].arg
>>> node.body[0].value.keywords[0].arg
'xxxxxxxxxxa'

this makes impossible to locate the keyword in the code using the AST as it lacks AST attributes (lineno, col_offset, end_lineno, end_col_offset).

On the other hand, this does not happen with args, that has the meta-information:

>>> node.body[0].value.args[0].id
'a'
>>> dir(node.body[0].value.args[0])


So one can locate the arg string using:

>>> r[arg.col_offset:arg.end_col_offset]
'a'

For this reason, we should add the same information to keyword nodes.

I am preparing more PRs for other nodes that are missing the meta-information as well but will open them in a separate issue.

New changeset 168660b547d5f683c5d3c60447cfa8c6d620efc3 by Pablo Galindo in branch 'master':
bpo-40141: Add line and column information to ast.keyword nodes (GH-19283)
https://github.com/python/cpython/commit/168660b547d5f683c5d3c60447cfa8c6d620efc3

New changeset 40cf35c5b070b3f33aae58a996fea0e8291a8616 by Pablo Galindo in branch 'master':
bpo-40141: Include the value in the column position for keyword AST nodes (GH-19348)
https://github.com/python/cpython/commit/40cf35c5b070b3f33aae58a996fea0e8291a8616