I have a python function x that returns some module x(): return y
I would like to parse the file x is located in and learn that "x returns this thing called 'y'". I have no idea how.
I'm not trying to get the type of the return type, just what the programmer calls exactly what is being returned.
ast moduleimport ast
def extract_return(file, fname):
for x in ast.walk(ast.parse(open(file).read())):
if not(isinstance(x, ast.FunctionDef)):
continue
if not(x.name == fname):
continue
for b in x.body:
if isinstance(b, ast.Return):
if isinstance(b.value, ast.Name):
yield b.value.id
This defines a function which takes some python source's filename and a function name fname (your "x") and yields each identifier returned by function fname. Here, I assume that you are only interested in return statements that occur at the first level of function x and consequently, I don't visit subexpressions. Also, I'am using yield because in more general cases this could work like a filter which could be composed with other ones. In more complex cases, it can be preferable to subclass ast.NodeVisitor.
This is equivalent in size with the regex approach but far more reliable.
It seems like you could hack something together with regexes pretty quickly.
Pseudocode:
import re
from collections import defaultdict
def findReturns(program_string):
result = defaultdict(list)
func_name = None
for line in re.findall('def .+\w|(?<=return ).+', program_string):
if line.startswith('def '):
func_name = line[4:]
continue
result[func_name].append(line)
return result
returned_object.__name__?