python - 使用 grep 或 awk 从 python 文件中提取文档字符串

Question

我想使用 grep 或 awk 从 python 文件中提取所有文档字符串。 我试过了

cat test.py | grep """[\w\W]*?"""

但我没有看到任何输出。 假设测试 test.py 看起来像这样。

import libraries

class MyClass(object):
    """Docstring to this class. 
       second line of docstring."""

    def myClassMethod(a,b):
        """Docstring of the method. 
           another line in docstring of the method."""
        return a + b

那么输出应该是所有用三引号括起来的内容。

"""Docstring to this class. 
second line of docstring."""
"""Docstring of the method. 
another line in docstring of the method."""

Answer 1

从 Python 代码中提取文档字符串的正确方法是通过实际的 Python 解析器(ast 模块):

#!/usr/bin/env python
import ast

with open('/path/to/file') as f:
    code = ast.parse(f.read())

for node in ast.walk(code):
    if isinstance(node, (ast.FunctionDef, ast.ClassDef, ast.Module)):
        docstring = ast.get_docstring(node)
        if docstring:
            print(repr(docstring))

运行您的示例将输出:

'Docstring to this class. \nsecond line of docstring.'
'Docstring of the method. \nanother line in docstring of the method.'

---

只是为了好玩，我们也可以使用 GNU awk 来实现:

$ awk -v RS= -v FPAT="'''.*'''|"'""".*"""' '{print $1}' file
"""Docstring to this class. 
       second line of docstring."""
"""Docstring of the method. 
           another line in docstring of the method."""