[MacPorts] #57344: mpv dose not work niether variants nor info with Error: No python variant selected when variants.conf has +python37

[MacPorts]

#57344: mpv dose not work niether variants nor  info with Error: No python variant
selected when variants.conf has +python37
------------------------+----------------------
  Reporter:  stanimura  |      Owner:  Ionic
      Type:  defect     |     Status:  assigned
  Priority:  Normal     |  Milestone:
 Component:  ports      |    Version:  2.5.3
Resolution:             |   Keywords:
      Port:  mpv        |
------------------------+----------------------

Comment (by chrstphrchvz):

 To be clear, the proposed changes intend to add a subport for Python 3.7,
 and replace (obsolete) all pre-3.7 subports with the 3.7 subport, correct?

 I'm not too familiar with Tcl syntax, but I think this line:
 {{{
 dict set python.legacy_versions 35 36 37
 }}}
 is invalid, and would lead to some error like
 {{{
 missing value to go with key
 while evaluating dict set python.legacy_versions 35 36 37
 }}}

 If the 3.6 subport is being obsoleted by the 3.7 subport, and the 3.5
 subport has been obsolete long enough that it can be removed, could the
 changes then just be:
 {{{
 -set python.versions         {27 36}
 +set python.versions         {27 37}
 -# Remove after 07-30-2018.
 +# Remove (or comment out, until Python 3.8 released?) after 2020-mm-dd
 -dict set python.legacy_versions 35 36
 +dict set python.legacy_versions 36 37
 }}}

-- 
Ticket URL: <https://trac.macports.org/ticket/57344#comment:4>
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