export a list as a csv file in python and getting UnicodeEncodeError

In another answer, you said you were using Python 2.7. Extract from Python Standard Library Reference Manual - csv module :

The csv module doesn’t directly support reading and writing Unicode, but it is 8-bit-clean save for some problems with ASCII NUL characters. So you can write functions or classes that handle the encoding and decoding for you as long as you avoid encodings like UTF-16 that use NULs. UTF-8 is recommended.

Same paragraph gives you an example of a class that could be used to deal with unicode data :

class UnicodeWriter:
    """
    A CSV writer which will write rows to CSV file "f",
    which is encoded in the given encoding.
    """

    def __init__(self, f, dialect=csv.excel, encoding="utf-8", **kwds):
        # Redirect output to a queue
        self.queue = cStringIO.StringIO()
        self.writer = csv.writer(self.queue, dialect=dialect, **kwds)
        self.stream = f
        self.encoder = codecs.getincrementalencoder(encoding)()

    def writerow(self, row):
        self.writer.writerow([s.encode("utf-8") for s in row])
        # Fetch UTF-8 output from the queue ...
        data = self.queue.getvalue()
        data = data.decode("utf-8")
        # ... and reencode it into the target encoding
        data = self.encoder.encode(data)
        # write to the target stream
        self.stream.write(data)
        # empty queue
        self.queue.truncate(0)

    def writerows(self, rows):
        for row in rows:
            self.writerow(row)

But you could also try simpler code :

import csv    
with open("output.csv", "wb") as f:
    writer = csv.writer(f)
    writer.writerows([u.encode('utf-8') for u in temp])

if temp is a list of unicode strings

or :

import csv    
with open("output.csv", "wb") as f:
    writer = csv.writer(f)
    writer.writerows([[u.encode('utf-8') for u in row] for row in temp])

if temp is a list of list of unicode strings