Error in using os.path.walk() correctly - python-3.x

Question

So I created this Folder C:\TempFiles to test run the following code snippet
Inside this folder i had two files -> nd1.txt, nd2.txt and a folder C:\TempFiles\Temp2, inside which i had only one file nd3.txt
Now when i execute this code:-
import os,file,storage
database = file.dictionary()
tools = storage.misc()
lui = -1 # last used file index
fileIndex = 1
def sendWord(wrd, findex): # where findex is the file index
global lui
if findex!=lui:
tools.refreshRecentList()
lui = findex
if tools.mustIgnore(wrd)==0 and tools.toRecentList(wrd)==1:
database.addWord(wrd,findex) # else there's no point adding the word to the database, because its either trivial, or has recently been added
def showPostingsList():
print("\nPOSTING's LIST")
database.display()
def parseFile(nfile, findex):
for line in nfile:
pl = line.split()
for word in pl:
sendWord(word.lower(),findex)
def parseDirectory(dirname):
global fileIndex
for root,dirs,files in os.walk(dirname):
for name in dirs:
parseDirectory(os.path.join(root,name))
for filename in files:
nf = open(os.path.join(root,filename),'r')
parseFile(nf,fileIndex)
print(" --> "+ nf.name)
fileIndex+=1
nf.close()
def main():
dirname = input("Enter the base directory :-\n")
print("\nParsing Files...")
parseDirectory(dirname)
print("\nPostings List has Been successfully created.\n",database.entries()," word(s) sent to database")
choice = ""
while choice!='y' and choice!='n':
choice = str(input("View List?\n(Y)es\n(N)o\n -> ")).lower()
if choice!='y' and choice!='n':
print("Invalid Entry. Re-enter\n")
if choice=='y':
showPostingsList()
main()
Now I should Traverse the three files only once each, and i put a print(filename) to test that, but apparently I am traversing the inside folder twice:-
Enter the base directory :-
C:\TempFiles
Parsing Files...
--> C:\TempFiles\Temp2\nd3.txt
--> C:\TempFiles\nd1.txt
--> C:\TempFiles\nd2.txt
--> C:\TempFiles\Temp2\nd3.txt
Postings List has Been successfully created.
34 word(s) sent to database
View List?
(Y)es
(N)o
-> n
Can Anyone tell me how to modify the os.path.walk() as such to avoid the error
Its not that my output is incorrect, but its traversing over one entire folder twice, and that's not very efficient.

Answer 1

Your issue isn't specific to Python 3, it's how os.walk() works - iterating already does the recursion to subfolders, so you can take out your recursive call:
def parseDirectory(dirname):
global fileIndex
for root,dirs,files in os.walk(dirname):
for filename in files:
nf = open(os.path.join(root,filename),'r')
parseFile(nf,fileIndex)
print(" --> "+ nf.name)
fileIndex+=1
nf.close()
By calling parseDirectory() for the dirs, you were starting another, independant walk of your only subfolder.