def count_holes(n, a = 0):
    try:
        assert isinstance(n, (str, int, long))
        n = int(n)
    except:
        return "ERROR"
    c = {'0': 1, '4': 1, '6': 1, '8': 2, '9': 1}
    for i in str(n):
        a += c.get(i, 0)
    return a

>>> value='000'
>>> str(value).lstrip('0')
''
>>>

assert isinstance(n, (str, int, long))

[guest@localhost nholes]$ python -m doctest nholes.doct2
**********************************************************************
File "nholes.doct2", line 108, in nholes.doct2
Failed example:
    f('1\n')
Expected:
    'ERROR'
Got:
    0
**********************************************************************
File "nholes.doct2", line 110, in nholes.doct2
Failed example:
    f('\n1')
Expected:
    'ERROR'
Got:
    0
**********************************************************************
File "nholes.doct2", line 112, in nholes.doct2
Failed example:
    f('1 ')
Expected:
    'ERROR'
Got:
    0
**********************************************************************
File "nholes.doct2", line 114, in nholes.doct2
Failed example:
    f(' 1')
Expected:
    'ERROR'
Got:
    0
**********************************************************************
1 items had failures:
   4 of  54 in nholes.doct2
***Test Failed*** 4 failures.
[guest@localhost nholes]$

>>> 69L
  File "<stdin>", line 1
    69L
      ^
SyntaxError: invalid syntax
>>>