Problem writing some strings (UnicodeEncodeError)

[Paulo da Silva]

Hi!

I am using a python3 script to produce a bash script from lots of
filenames got using os.walk.

I have a template string for each bash command in which I replace a
special string with the filename and then write the command to the bash
script file.

Something like this:

shf=open(bashfilename,'w')
filenames=getfilenames() # uses os.walk
for fn in filenames:
	...
	cmd=templ.replace("<fn>",fn)
	shf.write(cmd)

For certain filenames I got a UnicodeEncodeError exception at
shf.write(cmd)!
I use utf-8 and have # -*- coding: utf-8 -*- in the source .py.

How can I fix this?

Thanks for any help/comments.