# Run Parallel Python in Julia
**URL:** https://discourse.julialang.org/t/run-parallel-python-in-julia/34201
**Category:** General Usage
**Tags:** question
**Created:** [February 5, 2020, 10:48am UTC](https://discourse.julialang.org/t/run-parallel-python-in-julia/34201 "2020-02-05T10:48:40Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Impressium](https://discourse.julialang.org/u/Impressium)
#### Post date: [February 5, 2020, 10:48am UTC](https://discourse.julialang.org/t/run-parallel-python-in-julia/34201/1 "2020-02-05T10:48:41Z")
How does PyCall work under the hood. Can I run parallel python processes within Julia?
---
### Author:  [@longemen3000](https://discourse.julialang.org/u/longemen3000)
#### Post date: [February 5, 2020, 11:01am UTC](https://discourse.julialang.org/t/run-parallel-python-in-julia/34201/2 "2020-02-05T11:01:41Z")
I can’t find anything that saids that you can’t. Please try and show us if it worked or how it errored, it would be very helpful to have info on that
---
### Author:  [@Impressium](https://discourse.julialang.org/u/Impressium)
#### Post date: [February 5, 2020, 12:32pm UTC](https://discourse.julialang.org/t/run-parallel-python-in-julia/34201/3 "2020-02-05T12:32:26Z")
That’s what I get…
```julia
julia> for i in 1:5
Threads.@spawn py"1+1"
println(i)
end
Please submit a bug report with steps to reproduce this fault, and any error messages that follow (in their entirety). Thanks.
Exception: EXCEPTION_ACCESS_VIOLATION at 0x7ffe3c47ec92 -- ION with steps to reproduce this fault, and any error messages that follow (in their entirety). Thanks.
Exception: EXCEPTION_ACCESS_VIOLATIONEXCEPTION_ACCESS_VIOLA at 0x7ffe3c3df508 -- unknown function (ip: 00007FFE3C3DF508)
in expression starting at REPL[9]:0
unknown function (ip: 00007FFE3C3DF507)
unknown function (ip: 00007FFE3C3E1765)
unknown function (ip: 00007FFE3C3E0F11)
unknown function (ip: 00007FFE3C4D8846)
PyAST_FromNodeObject at C:\Users\\AppData\Local\Programs\Python\Python38\python38.dll (unknowin expression starting at REPL[9]:0
in expression starting at REPL[9]:0
ssbauer\AppData\Local\Programs\Python\Python38\python38.dll (unknown line)
PyArena_Free at C:\Users\\AppData\Local\Programs\Python\Python38\python38.dll (unknown line)
PyAST_FromNodeObject at C:\Users\\AppData\Local\Programs\Python\Python38\python38.dll (unknown line)
PyAST_FromNodeObject at C:\Users\\AppData\Local\Programs\Python\Python38\python38.dll (unknowPyAST_FromNodeObject at C:\Users\\AppData\Local\Programs\Python\Python38\python38.dll (unknown line)
PyParser_ASTFromStringObject at C:\Users\\AppData\Local\Programs\Python\Python38\python38.dll (unknown Py_CompileStringExFlags at C:\Users\\AppData\Local\Programs\Python\Python38\python38.dll (unknown line)
ne)
Py_CompileStringExFlags at C:\Users\\AppData\Local\Programs\Python\Python38\python38.dll (unknown line)
Py_CompileStringObject at C:\Users\\AppData\Local\Programs\Python\Python38\python38.dll (unknown line)
Py_CompileString at C:\Users\\AppData\Local\Programs\Python\Python38\python38.dll (unknown line)
Py_CompileStringExFlags at C:\Users\\AppData\Local\Programs\Python\Python38\python38.dll (unknown line)
macro expansion at C:\Users\\.julia\packages\PyCall\ttONZ\src\exception.jl:81 [inlined]
pyeval_ at C:\Users\\.julia\packages\PyCall\ttONZ\src\pyeval.jl:36
pyeval_ at C:\Users\\.julia\packages\PyCall\ttONZ\src\pyeval.jl:36
\python38.dll (unknown line)
macro expansion at C:\Users\\.julia\packages\PyCall\ttONZ\src\exception.jl:81 [inlined#6 at .\threadingconstructs.jl:113
unknown function (ip: 000000001DCBE383)
julia\packages\PyCall\ttONZ\src\exception.jl:81 [inlined]
pyeval_ at C:\Users\\.julia\packages\PyCall\ttONZ\src\pyeval.jl:36
macro expansion at C:\Users\\.julia\packages\PyCall\ttONZ\src\pyeval.jl:232 [inlined]
#6 at .\threadingconstructs.jl:113
unknown function (ip: 000000001DCBE383)
unknown function (ip: 000000001DCBE383)
_jl_invoke at /cygdrive/d/buildbot/worker/package_win64/build/src/cygdrive/d/buildbot/worker/package_win64/build/src\gf.c:2141 [inlined]
jl_apply_generic at /cygdrive/d/buildbot/worker/package_win64/build/src/cygdrive/d/buildbot/worker/package_win64/build/src\gf.c:2305
d]
jl_apply_generic at /cygdrive/d/buildbot/worker/package_win64/build/src/cygdrive/d/buildbot/worker/package_win64/build/src\gf.c:2305
jl_apply at /cygdrive/d/buildbot/worker/package_win64/build/src/cygdrive/d/buildbot/worker/package_win64/build/src\julia.h:1631 [inlijl_apply at /cygdrive/d/buildbot/worker/package_win64/build/src/cygdrive/d/buildbot/worker/package_win64/build/src\julia.h:1631 [inlined]
start_task at /cygdrive/d/buildbot/worker/package_win64/build/src/cygdrive/d/buildbot/worker/package_win64/build/src\task.c:659
Allocations: 7897480 (Pool: 7896151; Big: 1329); GC: 8
Allocations: 7897480 (Pool: 7896151; Big: 1329); GC: 8
ild/src/cygdrive/d/buildbot/worker/package_win64/build/src\julia.h:1631 [inlined]
start_task at /cygdrive/d/buildbot/worker/package_win64/build/src/cygdrive/d/buildbot/worker/package_win64/build/src\task.c:659
Allocations: 7897480 (Pool: 7896151; Big: 1329); GC: 8
```
---
### Author:  [@orialb](https://discourse.julialang.org/u/orialb)
#### Post date: [February 5, 2020, 1:37pm UTC](https://discourse.julialang.org/t/run-parallel-python-in-julia/34201/4 "2020-02-05T13:37:12Z")
Not sure if this helps for your use case, but from a quick check I made I think I am able to run `py"1+1"` on multiple worker processes using `pmap`. Do you need it to run on multiple threads or processes?
```julia
julia> using Distributed
julia> addprocs(2);
julia> @everywhere using PyCall
julia> @everywhere function pyfoo()
py"1+1"
end
julia> pmap(x->pyfoo(), 1:2)
2-element Array{Int64,1}:
2
2
```