So easy and works fine with proxy.

def upload2sharepoint(host_target,source_file):
    # (.Net) upload to Sharepoint...
    # it's that easy!
    wc = System.Net.WebClient()
    wc.Credentials=System.Net.CredentialCache.DefaultCredentials
    bytes = System.IO.File.ReadAllBytes(source_file)
    wc.UploadData(host_target,'PUT',bytes)