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3518 :: Detecting whether a module was imported or not

• CarlosH (orginal) [2018-02-01T21:21:19+01:00] view original

  In my module, I'd like to do something like

  when defined(nre):
    import nre
    # code that works with regular expressions
  Run

  so, if the user does

  import nre
  import my_module
  Run

  then that code gets compiled, but if the user doesn't use nre, then we aren't going to uselessly import it or compile the related code in my_module.

  Is something like that possible?

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• Araq (orginal) [2018-02-02T07:53:13+01:00] view original

  That's not how the import mechanism works, even if some other code imports nre, it's not in your scope. You can check for when declared(nre) in your code to see if you imported it on your own (if you have setup some complex include files this can be useful).

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• Stefan_Salewski (orginal) [2018-02-02T14:16:49+01:00] view original

  Araq, I think I can understand his intention:

  He wants to use nre module only, if it is used by other foreign modules already. Maybe to not unnecessary blow total executable size or to not introduce more new dependencies. Maybe, he has the task to search for a substring, so when nre is used already, he will use a proc of nre, otherwise he may prefer using his own nre-free plain textsearch proc.

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• cdome (orginal) [2018-02-02T15:59:38+01:00] view original

  Could be worth trying to go through list of loaded DLLs, shared objects in the current process?

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