Recursively search all files with multiple specified extensions

It's a guy who wants to search for jpg or png in one shot. Even if I searched on the net, I couldn't do it in one line. But with recursion, I couldn't do it in one line ... It's python2.7.

Not recursion

import glob
from compiler.ast import flatten

search_dir = "path/to/"
ext_list = ["jpg", "png"]

file_list = flatten([f for f in [glob.glob(search_dir + "*." + ext) for ext in ext_list]])

Another. This one was a little faster.

import os
import glob
from itertools import chain

search_dir = "path/to/"
ext_list = ["jpg", "png"]

file_list = list(chain.from_iterable([glob.glob(os.path.join(search_dir, "*." + ext)) for ext in ext_list]))

Recursion

・ If the number is small, this is

import os

search_dir = "path/to/"
ext_list = ["jpg", "png"]

file_list = []
for root, dirs, files in os.walk(search_dir):
    for ext in ext_list:
        file_list.extend([os.path.join(root, file) for file in files if ext in file])

・ If there are many files, it will be difficult to list them.

import os

#Prepare a function to recursively get a file with yield
def get_file_recursive(search_dir, ext_list):
    for root, dirs, files in os.walk(search_dir):
        for ext in ext_list:
            for file in [file for file in files if ext in file]:
                yield os.path.join(root, file)

search_dir = "path/to/"
ext_list = ["jpg", "png"]

file_list = get_file_recursive(search_dir, ext_list)