Downloading Webcomic Saving Blank Files - python

I have a script for downloading the Questionable Content webcomic. It looks like it runs okay, but the files it downloads are empty, only a few kb in size.
#import Web, Reg. Exp, and Operating System libraries
import urllib, re, os
#RegExp for the EndNum variable
RegExp = re.compile('.*<img src="http://www.questionablecontent.net/comics.*')
#Check the main QC page
site = urllib.urlopen("http://questionablecontent.net/")
contentLine = None
#For each line in the homepage's source...
for line in site.readlines():
#Break when you find the variable information
if RegExp.search(line):
contentLine = line
break
#IF the information was found successfuly automatically change EndNum
#ELSE set it to the latest comic as of this writing
if contentLine:
contentLine = contentLine.split('/')
contentLine = contentLine[4].split('.')
EndNum = int(contentLine[0])
else:
EndNum = 2622
#First and Last comics user wishes to download
StartNum = 1
#EndNum = 2622
#Full path of destination folder needs to pre-exist
destinationFolder = "D:\Downloads\Comics\Questionable Content"
#XRange creates an iterator to go over the comics
for i in xrange(StartNum, EndNum+1):
#IF you already have the comic, skip downloading it
if os.path.exists(destinationFolder+"\\"+str(i)+".png"):
print "Skipping Comic "+str(i)+"..."
continue
#Printing User-Friendly Messages
print "Comic %d Found. Downloading..." % i
source = "http://www.questionablecontent.net/comics/"+str(i)+".png"
#Save image from XKCD to Destination Folder as a PNG (As most comics are PNGs)
urllib.urlretrieve(source, os.path.join(destinationFolder, str(i)+".png"))
#Graceful program termination
print str(EndNum-StartNum) + " Comics Downloaded"
Why does it keep downloading empty files? Is there any workaround?

The problem here is that the server doesn't serve you the image if your user agent isn't set. Below is a sample code for Python 2.7, which should give you an idea regarding how to make your script work.
import urllib2
import time
first = 1
last = 2622
for i in range(first, last+1):
time.sleep(5) # Be nice to the server! And avoid being blocked.
for ext in ['png', 'gif']:
# Make sure that the img dir exists! If not, the script will throw an
# IOError
with open('img/{}.{}'.format(i, ext), 'wb') as ifile:
try:
req = urllib2.Request('http://www.questionablecontent.net/comics/{}.{}'.format(i, ext))
req.add_header('user-agent', 'Mozilla/5.0')
ifile.write(urllib2.urlopen(req).read())
break
except urllib2.HTTPError:
continue
else:
print 'Could not find image {}'.format(i)
continue
print 'Downloaded image {}'.format(i)
You may want to change your loop into something that resembles your loop (check whether the image has been downloaded previously etc.). This script will try to download all images from <start>.<ext> to <end>.<ext>, where <ext> is either gif or png.

Related

Downloading a file with a wildcard from Sharepoint URL with Python

I'm not sure if this can be done or not but I thought I'd ask!
I'm running a windows 10 PC using Python 2.7. I'm wanting to download a file form sharepoint to a folder on my C: drive.
OpenPath = "https://office.test.com/sites/Rollers/New improved files/"
OpenFile = "ABC UK.xlsb"
The downside is the file is uploaded externally & due to human error it can be saved as a .xlsx or ABC_UK. Therefor I only want to use the first 3 characters with a wildcard (ABC*) to open that file. Thankfully the first 3 Characters are unique & there only be one file in the path that should match.
to find the file in your dir:
import os, requests, fnmatch
#loop over dir
for filename in os.listdir(OpenPath):
#find the file
if fnmatch.fnmatch(filename, 'ABC_UK*'):
#download the file
# open file handler
with open('C:\dwnlfile.xls', 'wb') as fh:
#try to get it
result = requests.get(OpenPath+filename)
#check u got it
if not result.ok:
print result.reason # or text
exit(1)
#save it
fh.write(result.content)
print 'got it and saved'

Script downloads data files but I can't stop the script

Description of code
My script below works fine. It basically just finds all the data files that I'm interested in from a given website, checks to see if they are already on my computer (and skips them if they are), and lastly downloads them using cURL on to my computer.
The problem
The problem I'm having is sometimes there are 400+ very large files and I can't download them all at the same time. I'll push Ctrl-C but it seems to cancel the cURL download not the script so I end up needing to cancel all the downloads one by one. Is there a way around this? Maybe somehow making a key command that will let me stop at the end of the current download?
#!/usr/bin/python
import os
import urllib2
import re
import timeit
filenames = []
savedir = "/Users/someguy/Documents/Research/VLF_Hissler/Data/"
#connect to a URL
website = urllib2.urlopen("http://somewebsite")
#read html code
html = website.read()
#use re.findall to get all the data files
filenames = re.findall('SP.*?\.mat', html)
#The following chunk of code checks to see if the files are already downloaded and deletes them from the download queue if they are.
count = 0
countpass = 0
for files in os.listdir(savedir):
if files.endswith(".mat"):
try:
filenames.remove(files)
count += 1
except ValueError:
countpass += 1
print "counted number of removes", count
print "counted number of failed removes", countpass
print "number files less removed:", len(filenames)
#saves the file names into an array of html link
links=len(filenames)*[0]
for j in range(len(filenames)):
links[j] = 'http://somewebsite.edu/public_web_junk/southpole/2014/'+filenames[j]
for i in range(len(links)):
os.system("curl -o "+ filenames[i] + " " + str(links[i]))
print "links downloaded:",len(links)
You could always check the file size using curl before downloading it:
import subprocess, sys
def get_file_size(url):
"""
Gets the file size of a URL using curl.
#param url: The URL to obtain information about.
#return: The file size, as an integer, in bytes.
"""
# Get the file size in bytes
p = subprocess.Popen(('curl', '-sI', url), stdout=subprocess.PIPE)
for s in p.stdout.readlines():
if 'Content-Length' in s:
file_size = int(s.strip().split()[-1])
return file_size
# Your configuration parameters
url = ... # URL that you want to download
max_size = ... # Max file size in bytes
# Now you can do a simple check to see if the file size is too big
if get_file_size(url) > max_size:
sys.exit()
# Or you could do something more advanced
bytes = get_file_size(url)
if bytes > max_size:
s = raw_input('File is {0} bytes. Do you wish to download? '
'(yes, no) '.format(bytes))
if s.lower() == 'yes':
# Add download code here....
else:
sys.exit()

Set output location for python script

I want to save all images from a site. wget is horrible, at least for http://www.leveldesigninspirationmachine.tumblr.com since in the image folder it just drops html files, and nothing as an extension.
I found a python script, the usage is like this:
[python] ImageDownloader.py URL MaxRecursionDepth DownloadLocationPath MinImageFileSize
Finally I got the script running after some BeautifulSoup problems.
However, I can't find the files anywhere. I also tried "/" as the output dir in hope the images got on the root of my HD but no luck. Can someone either help me to simplify the script so it outputs at the cd directory set in terminal. Or give me a command that should work. I have zero python experience and I don't really want to learn python for a 2 year old script that maybe doesn't even work the way I want.
Also, how can I pass an array of website? With a lot of scrapers it gives me the first few results of the page. Tumblr has the load on scroll but that has no effect so i would like to add /page1 etc.
thanks in advance
# imageDownloader.py
# Finds and downloads all images from any given URL recursively.
# FB - 201009094
import urllib2
from os.path import basename
import urlparse
#from BeautifulSoup import BeautifulSoup # for HTML parsing
import bs4
from bs4 import BeautifulSoup
global urlList
urlList = []
# recursively download images starting from the root URL
def downloadImages(url, level, minFileSize): # the root URL is level 0
# do not go to other websites
global website
netloc = urlparse.urlsplit(url).netloc.split('.')
if netloc[-2] + netloc[-1] != website:
return
global urlList
if url in urlList: # prevent using the same URL again
return
try:
urlContent = urllib2.urlopen(url).read()
urlList.append(url)
print url
except:
return
soup = BeautifulSoup(''.join(urlContent))
# find and download all images
imgTags = soup.findAll('img')
for imgTag in imgTags:
imgUrl = imgTag['src']
# download only the proper image files
if imgUrl.lower().endswith('.jpeg') or \
imgUrl.lower().endswith('.jpg') or \
imgUrl.lower().endswith('.gif') or \
imgUrl.lower().endswith('.png') or \
imgUrl.lower().endswith('.bmp'):
try:
imgData = urllib2.urlopen(imgUrl).read()
if len(imgData) >= minFileSize:
print " " + imgUrl
fileName = basename(urlsplit(imgUrl)[2])
output = open(fileName,'wb')
output.write(imgData)
output.close()
except:
pass
print
print
# if there are links on the webpage then recursively repeat
if level > 0:
linkTags = soup.findAll('a')
if len(linkTags) > 0:
for linkTag in linkTags:
try:
linkUrl = linkTag['href']
downloadImages(linkUrl, level - 1, minFileSize)
except:
pass
# main
rootUrl = 'http://www.leveldesigninspirationmachine.tumblr.com'
netloc = urlparse.urlsplit(rootUrl).netloc.split('.')
global website
website = netloc[-2] + netloc[-1]
downloadImages(rootUrl, 1, 50000)
As Frxstream has commented, this program creates the files in the current directory (i.e. where you run it). After running the program, run ls -l (or dir) to find the files it has created.
If it seemingly hasn't created any files, then most probably it really hasn't created any files, most probably because there was an exception which your except: pass has hidden. To see what was going wrong, replace try: ... except: pass with just ..., and rerun the program. (If you can't understand and fix that, ask a separate StackOverflow question.)
it's hard to tell without looking at the errors (+1 to turning off your try/except block so you can see the exceptions) but I do see one typo here:
fileName = basename(urlsplit(imgUrl)[2])
you didn't do "from urlparse import urlsplit" you have "import urlparse" so you need to refer to it as urlparse.urlsplit() as you have in other places, so should be like this
fileName = basename(urlparse.urlsplit(imgUrl)[2])

downloading large number of files using python

test.txt contains the list of files to be downloaded:
http://example.com/example/afaf1.tif
http://example.com/example/afaf2.tif
http://example.com/example/afaf3.tif
http://example.com/example/afaf4.tif
http://example.com/example/afaf5.tif
How these files can be downloaded using python with maximum download speed?
my thinking was as follows:
import urllib.request
with open ('test.txt', 'r') as f:
lines = f.read().splitlines()
for line in lines:
response = urllib.request.urlopen(line)
What after that?How to select download directory?
Select a path to your desired output directory (output_dir). In your for loop split every url on / character and use the last peace as the filename. Also open the files for writing in binary mode wb since the response.read() returns bytes, not str.
import os
import urllib.request
output_dir = 'path/to/you/output/dir'
with open ('test.txt', 'r') as f:
lines = f.read().splitlines()
for line in lines:
response = urllib.request.urlopen(line)
output_file = os.path.join(output_dir, line.split('/')[-1])
with open(output_file, 'wb') as writer:
writer.write(response.read())
Note:
Downloading multiple files can be faster if you use multiple threads since the download is rarely using the full bandwidth of your internet connection._
Also if the files you are downloading are pretty big you should probably stream the read (reading chunk by chunk). As #Tiran commented you should use shutil.copyfileobj(response, writer) instead of writer.write(response.read()).
I would only add that you should probably always specify the length parameter too: shutil.copyfileobj(response, writer, 5*1024*1024) # (at least 5MB) since the default value of 16kb is really small and it will just slow things down.
This works fine for me: (note that name must be absolute, for example 'afaf1.tif')
import urllib,os
def download(baseUrl,fileName,layer=0):
print 'Trying to download file:',fileName
url = baseUrl+fileName
name = os.path.join('foldertodwonload',fileName)
try:
#Note that folder needs to exist
urllib.urlretrieve (url,name)
except:
# Upon failure to download retries total 5 times
print 'Download failed'
print 'Could not download file:',fileName
if layer > 4:
return
else:
layer+=1
print 'retrying',str(layer)+'/5'
download(baseUrl,fileName,layer)
print fileName+' downloaded'
for fileName in nameList:
download(url,fileName)
Moved unnecessary code out from try block

Download big zip file with python

I have multiple URLs that returns zip files. Most of the files, I'm able to download using urllib2 library as follows:
request = urllib2.urlopen(url)
zip_file = request.read()
The problem I'm having is that one of the files is 35Mb in size (zipped) and I'm never able to finish downloading it using this library. I'm able to download it using wget and the browser normally.
I have tried downloading the file in chuncks like this:
request = urllib2.urlopen(url)
buffers = []
while True:
buffer = request.read(8192)
if buffer:
buffers.append(buffer)
else:
break
final_file = ''.join(buffers)
But this also does not finish the download. No error is raised, so it's hard to debug what is happening. Unfortunately, I can't post an example of the url / file here.
Any suggestions / advices?
This is copy / paste from my application which downloads it's own update installer. It reads the file in blocks and immediately saves the blocks in output file on the disk.
def DownloadThreadFunc(self):
try:
url = self.lines[1]
data = None
req = urllib2.Request(url, data, {})
handle = urllib2.urlopen(req)
self.size = int(handle.info()["Content-Length"])
self.actualSize = 0
name = path.join(DIR_UPDATES, url.split("/")[-1])
blocksize = 64*1024
fo = open(name, "wb")
while not self.terminate:
block = handle.read(blocksize)
self.actualSize += len(block)
if len(block) == 0:
break
fo.write(block)
fo.close()
except (urllib2.URLError, socket.timeout), e:
try:
fo.close()
except:
pass
error("Download failed.", unicode(e))
I use self.size and self.actualSize to show the download progress in GUI thread and self.terminate to cancel the download from the GUI button if needed.

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