CODEWITHSUNDEEP
pythonpandas
user131983
user131983

Reputation: 3937

Bad Zip File error when rewriting code in Python 3.4

I am trying to rewrite code previously written for Python 2.7 into Python 3.4. I get the error zipfile.BadZipFile: File is not a zip file in the line zipfile = ZipFile(StringIO(zipdata)) in the code below.

import csv
try:
    from StringIO import StringIO
except ImportError:
    from io import StringIO
import pandas as pd
import os
from zipfile import ZipFile
from pprint import pprint, pformat
import urllib.request
import urllib.parse

try:
    import urllib.request as urllib2
except ImportError:
    import urllib2

my_url = 'http://www.bankofcanada.ca/stats/results/csv'
data = urllib.parse.urlencode({"lookupPage": "lookup_yield_curve.php",
                         "startRange": "1986-01-01",
                         "searchRange": "all"})
# request = urllib2.Request(my_url, data)
# result = urllib2.urlopen(request)
binary_data = data.encode('utf-8')
req = urllib.request.Request(my_url, binary_data)
result = urllib.request.urlopen(req)


zipdata = result.read().decode("utf-8",errors="ignore")
zipfile = ZipFile(StringIO(zipdata))

df = pd.read_csv(zipfile.open(zipfile.namelist()[0]))

df = pd.melt(df, id_vars=['Date'])

df.rename(columns={'variable': 'Maturity'}, inplace=True)

Thank You

Upvotes: 1

Views: 1856

Answers (1)

strubbly
strubbly

Reputation: 3507

You shouldn't be decoding the data you get back in the result. The data is the bytes for the ZipFile, not bytes which are the encoding of a unicode string. I think your confusion arises because in Python 2 there is no distinction, but here in Python 3 you need a BytesIO not a StringIO.

So that part of your code should read:

zipdata = result.read()

zipfile = ZipFile(BytesIO(zipdata))

df = pd.read_csv(zipfile.open(zipfile.namelist()[0]))

The data you are getting back is not utf-8 encoded so you can't decode it that way. You would have found that more easily if you hadn't specified errors = "ignore", which is seldom a good idea ...

Upvotes: 1

Related Questions