Question

I am trying to have a file path like ‘C:\Programfiles\file.txt’ but i would like to have file.txt be a variable that i can change whenever i need to. I am trying to compare 2 directories then copy files from one to another if they arent already there. i have this code so far.

import os
import shutil
A= set(os.listdir(r"C:\Users\Morpheous\Desktop\Python Test"))
B= set(os.listdir(r"C:\Users\Morpheous\Desktop\Python Test 2"))
if len(A)< len(B):
    C=B-A
    print("File is: %s" %(C))
    shutil.copy2('C:\\Users\\Morpheous\\Desktop\\Python Test 2\\%r'%(C),'C:\\Users\\Morpheous\\Desktop\\Python Test')

elif len(A) > len(B):
    C=B-A
    print(C)

and i get an error because the variable is inserted into path with {”} around it. How would i go about doing this?

Answer 1

Please use os.path.join to construct paths. Also, you should put the directories in variables for reuse. Furthermore you need to iterate over the difference between the folders (B - A) in order to get each filename that’s in the difference set (C is the set of files that have been added!).

Here’s the corrected version – tested and working:

import os
import shutil

pathA = r"C:\Users\Morpheous\Desktop\Python Test"
pathB = r"C:\Users\Morpheous\Desktop\Python Test 2"

A = set(os.listdir(pathA))
B = set(os.listdir(pathB))
C = B - A

if len(C):
    print("Difference is: %s" % repr(C))

    for addedFile in C:
        shutil.copy2(os.path.join(pathB, addedFile),
                     os.path.join(pathA, addedFile))
else:
    print("No new files")