import urllib2

username = 's5pguest'
password = 's5pguest'

#This should be the base url you wanted to access.
baseurl = "https://s5phub.copernicus.eu/dhus/odata/v1/Products('56c22bb9-f91d-40de-9bc8-3ddf23fc2fb0')/$value"

#Create a password manager
manager = urllib2.HTTPPasswordMgrWithDefaultRealm()
manager.add_password(None, baseurl, username, password)

#Create an authentication handler using the password manager
auth = urllib2.HTTPBasicAuthHandler(manager)

#Create an opener that will replace the default urlopen method on further calls
opener = urllib2.build_opener(auth)
urllib2.install_opener(opener)

#Here you should access the full url you wanted to open
response = urllib2.urlopen(baseurl + "/file")