def download_large_file(url, path, md5sum=None):
""" Downloads large file from :url: to :path:
:url: unicode
url of file to download
:path: unicode
location where to download the file
:md5sum: unicode [optional]
md5 checksum
"""
# download file and compute md5
md5 = hashlib.md5()
with closing(urllib2.urlopen(url)) as request:
# read file size from headers
file_size = int(request.info().getheaders('Content-Length')[0])
print 'file size:', human_readable_size(file_size)
progressbar = ProgressBar(file_size)
with open(path, 'wb') as output_file:
while True:
chunk = request.read(CHUNK)
if not chunk:
break
output_file.write(chunk)
md5.update(chunk)
progressbar.add(len(chunk))
progressbar.finish()
# check MD5 checksum
if md5sum:
if md5.hexdigest() == md5sum:
print 'MD5 checksum: OK'
else:
print 'Wrong MD5 checksum! Try download the file again.'
