installing pydns

I try to install pydns with python3 -m pip install pydns but get an error saying

Downloading/unpacking pydns
  Downloading pydns-2.3.6.tar.gz
  Running setup.py (path:/tmp/pip_build_root/pydns/setup.py) egg_info for package pydns
    Traceback (most recent call last):
      File "<string>", line 17, in <module>
      File "/tmp/pip_build_root/pydns/setup.py", line 12, in <module>
        import DNS
      File "/tmp/pip_build_root/pydns/DNS/__init__.py", line 14, in <module>
        import Type,Opcode,Status,Class
    ImportError: No module named 'Type'
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):

  File "<string>", line 17, in <module>

  File "/tmp/pip_build_root/pydns/setup.py", line 12, in <module>

    import DNS

  File "/tmp/pip_build_root/pydns/DNS/__init__.py", line 14, in <module>

    import Type,Opcode,Status,Class

ImportError: No module named 'Type'

Then I tried

python3 -m pip install pytype
Downloading/unpacking pytype
  Downloading pytype-2019.1.18.tar.gz (979kB): 979kB downloaded
  Running setup.py (path:/tmp/pip_build_root/pytype/setup.py) egg_info for package pytype
    error in pytype setup command: 'install_requires' must be a string or list of strings containing valid project/version requirement specifiers
    Complete output from command python setup.py egg_info:
    error in pytype setup command: 'install_requires' must be a string or list of strings containing valid project/version requirement specifiers

What can I do to get policyd-spf running?

# /usr/bin/policyd-spf
Traceback (most recent call last):
  File "/usr/bin/policyd-spf", line 39, in <module>
    import spf
  File "/usr/lib/python3.4/site-packages/spf.py", line 110, in <module>
    import DNS # http://pydns.sourceforge.net
ImportError: No module named 'DNS'

Thank you!

Kind regards

  Andreas