indentation error with python 3.3 when python2.7 works well

Question

I wrote this script below which converts number to it's spelling.

no = raw_input("Enter a number: ")

strcheck = str(no)
try:
     val = int(no)
except ValueError:
     print("sayi degil")
     raise SystemExit
lencheck = str(no)
if len(lencheck) > 6:
     print("Bu sayi cok buyuk !")
     raise SystemExit

n = int(no)
print(n)
def int2word(n):

     n3 = []
     r1 = ""

     ns = str(n)
     for k in range(3, 33, 3):
              r = ns[-k:]
              q = len(ns) - k

    if q < -2:
        break
    else:
        if  q >= 0:
            n3.append(int(r[:3]))
        elif q >= -1:
            n3.append(int(r[:2]))
        elif q >= -2:
            n3.append(int(r[:1]))
    r1 = r

#print(n3)  


     nw = ""
     for i, x in enumerate(n3):
              b1 = x % 10
              b2 = (x % 100)//10
              b3 = (x % 1000)//100

          if x == 0:
                  continue  
              else:
                  t = binler[i]

              if b2 == 0:
                  nw = birler[b1] + t + nw
              elif b2 == 1:
                  nw = onlar[1] + birler[b1] + t + nw
              elif b2 > 1:
                  nw = onlar[b2] + birler[b1] + t + nw
              if b3 > 0:
                  nw = birler[b3] + "yuz " + nw
     return nw

 birler = ["", " ","iki ","uc ","dort ", "bes ", "alti ","yedi ","sekiz ","dokuz "]
 onlar = ["", "on ", "yirmi ", "otuz ", "kirk ", "elli ", "altmis ", "yetmis ", "seksen ", "doksan "]
 binler = ["", "bin"]

 print int2word(n)

This scripts works pretty well on Python2.7.

But when I try to run it with python3.3

It gives me error below:

File "numtospell.py", line 58
    if x == 0:
             ^
TabError: inconsistent use of tabs and spaces in indentation

I've googled it for hours but cannot find a suitable solution. What do I do to fix this?

Thanks for any help.

Answer 1

You are mixing tabs and spaces.

Python 3 explicitly disallows this. Use spaces only for indentation.

Quoting from the Python Style Guide (PEP 8):

Spaces are the preferred indentation method.

Tabs should be used solely to remain consistent with code that is already indented with tabs.

Python 3 disallows mixing the use of tabs and spaces for indentation.

Emphasis mine.

Almost all editors can be configured to replace tabs with spaces when typing, as well as do a search and replace operation that replaces existing tabs with spaces.