Q. on a TypeError.

[Wayne]

Hello,
I'm using Python 1.5.2 on a Linux system.
I wrote a little program to format a printed report. I'm get an error
which I don't understand
why I'm getting it.

The line of code in question is:
    nbr_of_spaces = blk_sz_value - len(entry['fld_value'])

     TypeError: len() of unsize object

  The value that is in question is a date and there is a value in the
dictionary.
  So , can someone explain why I'm getting such an error?
TIA.
Wayne