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Python Entry Points Explained

by Nurdok on 7/28/17, 12:51 PM with 13 comments

• by rajathagasthya on 7/28/17, 1:30 PM

  I highly recommend reading Stevedore package's excellent documentation [1] to see practical examples of how entry points can be used as a plugin manager in applications.

  [1] - https://docs.openstack.org/stevedore/latest/index.html

• by jwilk on 7/28/17, 3:16 PM

  Entry points are excellent at making your scripts start slooooooooow.

  Compare

    $ time python -m pyflakes /dev/null
    
    real	0m0.225s
    user	0m0.103s
    sys	0m0.008s
  

  with

    $ time pyflakes /dev/null
    
    real	0m2.468s
    user	0m1.738s
    sys	0m0.055s

• by pmoriarty on 7/28/17, 2:07 PM

  Way too much ink wasted on cuteness and too little on explanation.

  I got stumped at:

  "In particular, the magic happens in get_sneks. The call to pkg_resources.iter_entry_points('snek_types') iterates over all the entry points that were registered under the name "snek_types". So, external packages can define an entry point called "snek_types" in their setup.py, and snek will dynamically load it at runtime."

  Wait. What entry points were registered under the name "snek_types"? Where were they regeistered as such? I think I must be missing something, or maybe that registration was hidden somewhere among all the fancy snakes. Can someone help explain this in a clearer way?

• by sjburt on 7/28/17, 9:59 PM

  What is the actual value of entry points over just marking a script +x and putting somewhere on the path? All I see is a bunch of added complexity.