Q:

urlopen trouble while trying to download a gzip file

I am going to use the wiktionary dump for the purpose of POS tagging.  Somehow it gets stuck when downloading.  Here is my code:
import nltk
from urllib import urlopen
from collections import Counter
import gzip

url = 'http://dumps.wikimedia.org/enwiktionary/latest/enwiktionary-latest-all-titles-in-ns0.gz'
fStream = gzip.open(urlopen(url).read(), 'rb')
dictFile = fStream.read()
fStream.close()

text = nltk. Text(word.lower() for word in dictFile())
tokens = nltk.word_tokenize(text)

Here is the error I get:
Traceback (most recent call last):
File "~/dir1/dir1/wikt.py", line 15, in <module>
fStream = gzip.open(urlopen(url).read(), 'rb')
File "/usr/lib/python2.7/gzip.py", line 34, in open
return GzipFile(filename, mode, compresslevel)
File "/usr/lib/python2.7/gzip.py", line 89, in __init__
fileobj = self.myfileobj = __builtin__.open(filename, mode or 'rb')
TypeError: file() argument 1 must be encoded string without NULL bytes, not str
Process finished with exit code 1

A:

You are passing the downloaded data to gzip.open(), which expects to be passed a filename instead. 
The code then tries to open a filename named by the gzipped data, and fails. 
Either save the URL data to a file, then use gzip.open() on that, or decompress the gzipped data using the zlib module instead. ' Saving' the data can be as easy as using a StringIO.StringIO() in-memory file object:
from StringIO import StringIO
from urllib import urlopen
import gzip

url = 'http://dumps.wikimedia.org/enwiktionary/latest/enwiktionary-latest-all-titles-in-ns0.gz'
inmemory = StringIO(urlopen(url).read())
fStream = gzip. GzipFile(fileobj=inmemory, mode='rb')

