$ sudo apt-get dist-upgrade
[sudo] password for andy:
Sorry, try again.
[sudo] password for andy:
Reading package lists... Done
Building dependency tree
Reading state information... Done
You might want to run 'apt-get -f install' to correct these.
The following packages have unmet dependencies:
 iotop : Depends: python (< 2.8) but 3.7.0-1 is installed
 python-acme : Depends: python:any (< 2.8)
               Depends: python:any (>= 2.7.5-5~)
 python-asn1crypto : Depends: python:any (< 2.8)
                     Depends: python:any (>= 2.7.5-5~)
 python-certifi : Depends: python (< 2.8) but 3.7.0-1 is installed
 python-cffi-backend : Depends: python (< 2.8) but 3.7.0-1 is installed
 python-chardet : Depends: python:any (< 2.8)
                  Depends: python:any (>= 2.7.5-5~)
 python-configparser : Depends: python (< 2.8) but 3.7.0-1 is installed
 python-crypto : Depends: python (< 2.8) but 3.7.0-1 is installed
                 Depends: python:any (>= 2.7.5-5~)
 python-cryptography : Depends: python (< 2.8) but 3.7.0-1 is installed
                       Depends: python:any (>= 2.7.5-5~)
 python-dnspython : Depends: python:any (< 2.8)
                    Depends: python:any (>= 2.7.5-5~)
 python-enum34 : Depends: python:any (< 2.8)
                 Depends: python:any (>= 2.7.5-5~)
 python-funcsigs : Depends: python:any (< 2.8)
                   Depends: python:any (>= 2.7.5-5~)
 python-future : Depends: python:any (< 2.8)
                 Depends: python:any (>= 2.7.5-5~)
 python-idna : Depends: python:any (< 2.8)
               Depends: python:any (>= 2.7.5-5~)
 python-ipaddress : Depends: python:any (< 2.8)
                    Depends: python:any (>= 2.7.5-5~)
 python-josepy : Depends: python:any (< 2.8)
                 Depends: python:any (>= 2.7.5-5~)
 python-ldb : Depends: python (< 2.8) but 3.7.0-1 is installed
              Depends: python:any (>= 2.7.5-5~)
 python-mock : Depends: python:any (< 2.8)
               Depends: python:any (>= 2.7.5-5~)
 python-openssl : Depends: python:any (< 2.8)
                  Depends: python:any (>= 2.7.5-5~)
 python-parsedatetime : Depends: python:any (< 2.8)
                        Depends: python:any (>= 2.7.5-5~)
 python-pbr : Depends: python:any (< 2.8)
              Depends: python:any (>= 2.7.5-5~)
 python-pkg-resources : Depends: python:any (< 2.8)
                        Depends: python:any (>= 2.7.5-5~)
 python-pyicu : Depends: python (< 2.8) but 3.7.0-1 is installed
 python-requests : Depends: python:any (< 2.8)
                   Depends: python:any (>= 2.7.5-5~)
 python-requests-toolbelt : Depends: python:any (< 2.8)
                            Depends: python:any (>= 2.7.5-5~)
 python-rfc3339 : Depends: python:any (< 2.8)
                  Depends: python:any (>= 2.7.5-5~)
 python-samba : Depends: python (< 2.8) but 3.7.0-1 is installed
 python-setuptools : Depends: python:any (< 2.8)
                     Depends: python:any (>= 2.7.5-5~)
 python-six : Depends: python:any (< 2.8)
              Depends: python:any (>= 2.7.5-5~)
 python-talloc : Depends: python (< 2.8) but 3.7.0-1 is installed
 python-tdb : Depends: python (< 2.8) but 3.7.0-1 is installed
              Depends: python:any (>= 2.7.5-5~)
 python-tz : Depends: python (< 2.8) but 3.7.0-1 is installed
 python-urllib3 : Depends: python:any (< 2.8)
                  Depends: python:any (>= 2.7.5-5~)
 samba : Depends: python (< 2.8) but 3.7.0-1 is installed
         Recommends: attr but it is not installed
         Recommends: samba-dsdb-modules but it is not installed
         Recommends: samba-vfs-modules but it is not installed
E: Unmet dependencies. Try using -f.

$ sudo apt-get -f dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Correcting dependencies... Done
Calculating upgrade... Done
The following packages will be REMOVED:
  iotop python-acme python-asn1crypto python-certifi python-cffi-backend python-chardet python-configparser python-crypto
  python-cryptography python-dnspython python-enum34 python-funcsigs python-future python-idna python-ipaddress python-josepy
  python-ldb python-mock python-openssl python-parsedatetime python-pbr python-pkg-resources python-pyicu python-requests
  python-requests-toolbelt python-rfc3339 python-samba python-setuptools python-six python-talloc python-tdb python-tz
  python-urllib3 samba samba-common-bin samba-libs
0 upgraded, 0 newly installed, 36 to remove and 0 not upgraded.
After this operation, 56.7 MB disk space will be freed.
Do you want to continue? [Y/n]