pipelines/sdk/python/kfp/cli/utils/parsing.py

70 lines
2.5 KiB
Python

# Copyright 2022 The Kubeflow Authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import re
from typing import Callable
def get_param_descr(fn: Callable, param_name: str) -> str:
"""Extracts the description of a parameter from the docstring of a function
or method. Docstring must conform to Google Style (https://sphinxcontrib-
napoleon.readthedocs.io/en/latest/example_google.html).
Args:
fn (Callable): The function of method with a __doc__ docstring implemented.
param_name (str): The parameter for which to extract the description.
Raises:
ValueError: If docstring is not found or parameter is not found in docstring.
Returns:
str: The description of the parameter.
"""
docstring = fn.__doc__
if docstring is None:
raise ValueError(
f'Could not find parameter {param_name} in docstring of {fn}')
lines = docstring.splitlines()
# collect all lines beginning after args, also get indentation space_chars
for i, line in enumerate(lines):
if line.lstrip().startswith('Args:'):
break
lines = lines[i + 1:]
first_already_found = False
return_lines = []
# allow but don't require type in docstring
first_line_args_regex = rf'^{param_name}( \(.*\))?: '
for line in lines:
if not first_already_found and re.match(first_line_args_regex,
line.lstrip()):
new_line = re.sub(first_line_args_regex, '', line.strip())
return_lines.append(new_line)
first_already_found = True
first_indentation_level = len(line) - len(line.lstrip())
continue
if first_already_found:
indentation_level = len(line) - len(line.lstrip())
if indentation_level <= first_indentation_level:
return ' '.join(return_lines)
else:
return_lines.append(line.strip())
raise ValueError(
f'Could not find parameter {param_name} in docstring of {fn}')