求教如何办到这个功能

import os                                      1
slist=[]                                       2
slist2=[]                                      3
##处理每进一个文件夹，就完成一次完全执行  
def oslist(dir_path,file_type):                4   
    for i in os.listdir(dir_path):             5
        abspath=os.path.join(dir_path , i)     6
        if os.path.isdir(abspath):             7
                oslist(abspath,file_type)      8
        else:slist.append(abspath)             9
              
    print(file_type)                           10
    if not file_type:                          11
        print('1')                             12

        return (slist  )                       13
    else:                                      14
        for i in slist:                        15
            if i.endswith(file_type):          16
               
                slist2.append(i)               17
                print('2')                     18
    return set(slist2)                         19
#本人想在9行完全执行以后（完全写完目录中所有file路径）再执行以后的步骤，现在的代码是每满足一次9的条件就会继续执行下面的代码，要求是在这个函数里完成，，不越出函数处理。谢谢大神了