Multiline evaluation

[charstnut]

Hi,
I am wondering if there is any API for multiline python code evaluation? I have gone through the documentation but was not able to find a clear example of this use case. Thank you for the help!

[cjdoris]

You can do

pyeval("""
x = 2
y = 3
print(x + y)
""")

and similar with @pyeval etc. Is this what you mean?

[charstnut]

Yes, thanks that's exactly what I meant. I was using the with open(...) as f: statements and that gives syntax error when evaluated. In that case do I have to use the pywith function?

[charstnut]

In fact I am getting MethodError and SyntaxError from python with the following two scenarios:

using PythonCall

pyeval("""
x = 2
y = 3
print(x + y)
""")

ERROR: LoadError: MethodError: no method matching pyeval(::String)
Closest candidates are:
  pyeval(::Any, ::Any) at ~/.julia/packages/PythonCall/d8Xcl/src/concrete/code.jl:47
  pyeval(::Any, ::Any, ::Any) at ~/.julia/packages/PythonCall/d8Xcl/src/concrete/code.jl:47
  pyeval(::Type{T}, ::Any, ::Any) where T at ~/.julia/packages/PythonCall/d8Xcl/src/concrete/code.jl:41

---

using PythonCall

pyeval("""
x = 2
y = 3
print(x + y)
""", Main)

ERROR: LoadError: Python: SyntaxError: invalid syntax (<string>, line 1)
Python stacktrace: none
Stacktrace:
  [1] pythrow()
    @ PythonCall ~/.julia/packages/PythonCall/d8Xcl/src/err.jl:94
  [2] errcheck
    @ ~/.julia/packages/PythonCall/d8Xcl/src/err.jl:10 [inlined]
  [3] pycallargs(f::Py, args::Py)
    @ PythonCall ~/.julia/packages/PythonCall/d8Xcl/src/abstract/object.jl:210
  [4] pycall(::Py, ::String, ::Vararg{Any}; kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ PythonCall ~/.julia/packages/PythonCall/d8Xcl/src/abstract/object.jl:228
  [5] pycall
    @ ~/.julia/packages/PythonCall/d8Xcl/src/abstract/object.jl:218 [inlined]
  [6] #_#13
    @ ~/.julia/packages/PythonCall/d8Xcl/src/Py.jl:358 [inlined]
  [7] Py
    @ ~/.julia/packages/PythonCall/d8Xcl/src/Py.jl:358 [inlined]
  [8] pyeval(::Type{Py}, code::String, globals::Module, locals::Nothing)
    @ PythonCall ~/.julia/packages/PythonCall/d8Xcl/src/concrete/code.jl:43
  [9] pyeval (repeats 2 times)
    @ ~/.julia/packages/PythonCall/d8Xcl/src/concrete/code.jl:47 [inlined]

[cjdoris]

Sorry I was mistaken. It's pyexec you need, which executes arbitrary Python code, whereas pyeval evaluates a single expression. And as you have discovered, you also need to specify the global scope (and optionally a local scope).

[cjdoris]

I think this is resolved.

[charstnut]

Thanks @cjdoris it works as intended!