python encoding error only when called as external process

The problem here is that in the second call you are basically writing to a pipe that only accepts bytestrings (file-like object). The same happens if you try to execute this:

python x.py > my_fileTraceback (most recent call last):File "x.py", line 2, in <module>    print xUnicodeEncodeError: 'ascii' codec can't encode character u'\xe8' in position 3: ordinal not in range(128)

As the receiver only understands bytestrings and not unicode characters you must first encode the unicode string into a bytestring using the encode function:

x = u'Gen\xe8ve'.encode('utf-8') print x

This will print the the unicode string encoded as a utf-8 bytestring (a sequence of bytes), allowing it to be written to a file-like object.

$echo $(python x.py)Genève$python x.py Genève

As you suspect, Python doesn't know how to print unicode when its standard output is not a known terminal. Consider encoding the string before printing it:

# coding: utf-8x = u'Gen\xe8ve'print x.encode("utf-8")

Note that the invoking program and your script will need to agree in a common encoding.