PythonCall not working in Jupyter Notebook in VSCode #601

Activity

1. AquaPore

   added

   bugSomething isn't workingSomething isn't working

   on Apr 8, 2025
2. cjdoris commented on Apr 9, 2025

   

   cjdoris

   on Apr 9, 2025

   Member

   More actions

   pyexec always returns nothing when called like that, it would have been the same in the REPL. In the REPL it probably just looked like it returned something because you print the answer inside fib.

   To extract values you can pass a named tuple type specifying what to keep, like

   pyexec(@NamedTuple{ans::BigInt}, """
   .......
   ans = fib(y)
   """, Main, (y=x,))

   Also see the @pyexec macro which makes this a bit easier.
3. AquaPore commented on Apr 9, 2025

   

   AquaPore

   on Apr 9, 2025

   Last edited by AquaPore

   Author

   More actions

   Hi Christopher,

   A great thanks for your kind help.

   Thanks for your suggestion by using pyexec, nevertheless, the following code still does not work as I get the following error message:

   cannot convert this Python 'NoneType' to a Julia 'BigInt'

   Did I do something wrong. Also I am confused why you suggest to use BigInt as I taught Float64 would be more appropriate.

   Many thanks for your kind help,
   Joseph

   function PYTHON_2_JULIA(x)
   
   fib(x) = pyexec(@NamedTuple{ans::BigInt},"""
   def fib(n):
       a, b = 0, 1
       while a < n:
           print(a, end=' ')
           a, b = b, a+b
       print()
   ans = fib(y)
   """, Main, (y=x,))
   
   C = fib(x)
   
   println(C)
   
   return C
   end
   
4. AquaPore commented on Apr 9, 2025

   

   AquaPore

   on Apr 9, 2025

   Author

   More actions

   I found an alternative solution by using as you suggested by using ** PythonCall.@PYEXEC**

   function PYTHON_2_JULIA(P_Int, P_Float, P_String, P_Vector)
   
       PythonCall.@pyexec """
           def PYTHON_2_JULIA(P_Int, P_Float, P_String, P_Vector):
               P_Int1 = P_Int + 1
               P_Float1 = P_Float * 2.0
               P_String1 = P_String + P_String 
               P_Vector1 = P_Vector + P_Vector
               return P_Int1, P_Float1, P_String1, P_Vector1
           """=> PYTHON_2_JULIA
   
       P_Int1, P_Float1, P_String1, P_Vector1 = PythonCall.pyconvert(Any, PYTHON_2_JULIA(P_Int, P_Float, P_String, P_Vector))
   
   return P_Int1, P_Float1, P_String1, P_Vector1
   end

   To run it:

   P_Int=1; P_Float=2.0; P_String=3; P_Vector = [1.0, 2.0, 3.0, 4.0]
   P_Int1, P_Float1, P_String1, P_Vector1 = .PYTHON_2_JULIA(P_Int, P_Float, P_String, P_Vector)

   @show P_Int1, P_Float1, P_String1, P_Vector1

   P_Vector1[1]

   This gives as expected

   (2, 4.0, 6, [2.0, 4.0, 6.0, 8.0])
   2.0
   
5. cjdoris commented on Apr 9, 2025

   

   cjdoris

   on Apr 9, 2025

   Member

   More actions

   Glad it's working now, I'll close the issue as resolved.

   BTW the reason the previous fib wasn't working is because it didn't actually return anything.
6. cjdoris

   closed this as completedon Apr 9, 2025
7. AquaPore commented on Apr 14, 2025

   

   AquaPore

   on Apr 14, 2025

   Author

   More actions

   Thanks @cjdoris , the idea is to wrap up some pyflwdir python package. Would you know how to call for e.g. numpy package into the example?

   Thanks for any help you may provide.