[MacPorts] #51994: Add py-filterpy port.

[MacPorts]

#51994: Add py-filterpy port.
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  Reporter:  KubaO        |      Owner:  macports-tickets@…
      Type:  submission   |     Status:  new
  Priority:  Normal       |  Milestone:
 Component:  ports        |    Version:  2.3.4
Resolution:               |   Keywords:
      Port:  py-filterpy  |
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Comment (by raimue):

 Normal github fetch seems to work fine, `github.master_sites` and
 `distname` are not needed.

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Ticket URL: <https://trac.macports.org/ticket/51994#comment:3>
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