pyhton Code of a folder in the total size of all files

1. recursive

DEF sum_file_size (File): 
    su = 0 
    RET = os.listdir (File)    # get all the files in the folder / folder name 
    for i in RET: 
        RES = os.path.join (File, i)   # the path splicing, the splicing is the absolute path to each file 
        iF os.path.isdir (RES):    # determine whether the folder 
            name_size = sum_file_size (RES) + su 
            su + = name_size
         elif os.path.isfile (RES ): 
            FILE_SIZE = os.path.getsize (RES) 
            SU + = FILE_SIZE
     return  SU
RES= sum_file_size(r'D:\flin')
print(res)

2. cycle to achieve

= li [R & lt ' D: \ FLIN ' ,] 
su_ = 0
 the while li:   # when li circulated to True when 
    A = li.pop ()   # value of the last deletion list element, the element returns 
    path_liat = os .listdir (a)   # get all the files in the folder / folder name 
    for i in path_liat: 
        RET = os.path.join (a, i)    # splicing path 
        IF os.path.isdir (RET) :    # determines whether the folder, if this path is added to the Li 
            li.append (RET)   
         elif the os.path.isfile (RET):    # if the file size of this file will be put adding 
            su_ + = os.path.getsize(ret)
print(su_)