[Zope] problem with zfill

[Adam Szpakowski]

Hi,

I've strange problem with using zfill in python scripts in Zope.

My script is simple:
--------------
import string
outa = str1.zfill(6)
return outa
--------------

str1 is a parameter given by interface. 

Running the script gives me:

Error Type: AttributeError
Error Value: 'str' object has no attribute 'zfill'

I understand the meaning of the error but why it's happening?

Others functions like:
outa = str1.upper()
works great. 

Zope is in version 2.6.1 and Python in 2.2.1.

Regards,

-- 
Adam Szpakowski
Silesian University of Technology - Institute of Physics
Department of Optoelectronic
e-mail: worf@optics.polsl.gliwice.pl