[Zope] Parsing a file through a Python script

[Pierre Godefroy]

I am trying to parse a file with a Python script (the file is stored in 
the same folder as the script) :
"marco" is the id of the file :

data=str(container.marco)
i=0
for line in data.readlines():
.....

I get a readlines : attribute error

Could anyone help me?

Sincerely,

Pierre Godefroy