name not defined error

[jolinchewjb]

in below program, i try to zip the files under 1139 directory.

import os
import datetime
import zipfile

def zipt(folder):
 folder = os.path.abspath(folder)
 ver = 1
 while True:
  zip_f = os.path.basename(folder)+'_'+str(ver)+'.zip'
  if not os.path.exsits(zip_f):
    break
  ver += 1
print("\narchiving %s..."%(zip_f))
zip_file=zipfile.ZipFile(zip_f,'w')
for foldername,subfolders,filenames in os.walk(folder):
 print("\nadding files in the %s..."%(foldername))
 zip_file.write(foldername)
 for filename in filenames:
  new_base=os.path.basename(folder)+'_'
  if filename.startswith(new_base) and filename.endswith('.zip'):
    continue
  zip_file.write(os.path.join(foldername,filename))
 zip_file.close()
 print("\narchiving complete, {} created successfully".format(zip_f))
 
 zipt('c:\\dell\\1139')

but it runs with error :
Traceback (most recent call last):
File "C:\dell\test_zip.py", line 13, in <module>
print("\narchiving %s..."%(zip_f))
NameError: name 'zip_f' is not defined

my zip_f is defined with os.path.basename(folder)+'_'+str(ver)+'.zip', why still error? thanks