`@pyexec` fails to define functions or set global variables

**Affects:** PythonCall

When I run `pyexec("x = 1", Main)`, it successfully sets the global variable. When, on the other hand, I run `@pyexec "x = 1"`, it does not. This extends to defining functions as well. It feels like a pretty serious bug to me. Maybe I'm misunderstanding how global environment management works?

```julia
julia> pyexec("x = 1", Main)

julia> pyeval("x", Main)
Python: 1

julia> @pyexec "y = 2"

julia> @pyeval "y"
ERROR: Python: NameError: name 'y' is not defined
Python stacktrace:
[1]
@ REPL[5]:1:1
Stacktrace:
[1] pythrow()
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/err.jl:94
[2] errcheck
@ ~/.julia/packages/PythonCall/qTEA1/src/err.jl:10 [inlined]
[3] pycallargs(f::Py, args::Py)
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/abstract/object.jl:210
[4] pycall(::Py, ::Py, ::Vararg{Py}; kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/abstract/object.jl:228
[5] pycall
@ ~/.julia/packages/PythonCall/qTEA1/src/abstract/object.jl:218 [inlined]
[6] #_#11
@ ~/.julia/packages/PythonCall/qTEA1/src/Py.jl:341 [inlined]
[7] Py
@ ~/.julia/packages/PythonCall/qTEA1/src/Py.jl:341 [inlined]
[8] pyeval(::Type{Py}, code::Py, globals::Module, locals::Tuple{})
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/concrete/code.jl:43
[9] top-level scope
@ ~/.julia/packages/PythonCall/qTEA1/src/concrete/code.jl:146
```

Full log

```julia
(@v1.9) pkg> activate --temp
Activating new project at `/var/folders/hc/fn82kz1j5vl8w7lwd4l079y80000gn/T/jl_NIT4tY`

(jl_NIT4tY) pkg> add PythonCall
[ Info: Use `./PythonCall` to add or develop the local directory at `~/.julia/dev/PythonCall`.
Resolving package versions...
Installed CondaPkg ─ v0.2.20
Updating `/private/var/folders/hc/fn82kz1j5vl8w7lwd4l079y80000gn/T/jl_NIT4tY/Project.toml`
[6099a3de] + PythonCall v0.9.14
Updating `/private/var/folders/hc/fn82kz1j5vl8w7lwd4l079y80000gn/T/jl_NIT4tY/Manifest.toml`
[992eb4ea] + CondaPkg v0.2.20
[9a962f9c] + DataAPI v1.15.0
[e2d170a0] + DataValueInterfaces v1.0.0
[82899510] + IteratorInterfaceExtensions v1.0.0
[692b3bcd] + JLLWrappers v1.5.0
[0f8b85d8] + JSON3 v1.13.2
[1914dd2f] + MacroTools v0.5.11
[0b3b1443] + MicroMamba v0.1.14
[bac558e1] + OrderedCollections v1.6.2
[69de0a69] + Parsers v2.7.2
[fa939f87] + Pidfile v1.3.0
[aea7be01] + PrecompileTools v1.2.0
[21216c6a] + Preferences v1.4.1
[6099a3de] + PythonCall v0.9.14
[ae029012] + Requires v1.3.0
[6c6a2e73] + Scratch v1.2.0
[856f2bd8] + StructTypes v1.10.0
[3783bdb8] + TableTraits v1.0.1
[bd369af6] + Tables v1.11.0
[e17b2a0c] + UnsafePointers v1.0.0
[f8abcde7] + micromamba_jll v1.4.9+0
[0dad84c5] + ArgTools v1.1.1
[56f22d72] + Artifacts
[2a0f44e3] + Base64
[ade2ca70] + Dates
[f43a241f] + Downloads v1.6.0
[7b1f6079] + FileWatching
[b77e0a4c] + InteractiveUtils
[4af54fe1] + LazyArtifacts
[b27032c2] + LibCURL v0.6.3
[76f85450] + LibGit2
[8f399da3] + Libdl
[37e2e46d] + LinearAlgebra
[56ddb016] + Logging
[d6f4376e] + Markdown
[a63ad114] + Mmap
[ca575930] + NetworkOptions v1.2.0
[44cfe95a] + Pkg v1.9.2
[de0858da] + Printf
[3fa0cd96] + REPL
[9a3f8284] + Random
[ea8e919c] + SHA v0.7.0
[9e88b42a] + Serialization
[6462fe0b] + Sockets
[fa267f1f] + TOML v1.0.3
[a4e569a6] + Tar v1.10.0
[8dfed614] + Test
[cf7118a7] + UUIDs
[4ec0a83e] + Unicode
[e66e0078] + CompilerSupportLibraries_jll v1.0.5+0
[deac9b47] + LibCURL_jll v7.84.0+0
[29816b5a] + LibSSH2_jll v1.10.2+0
[c8ffd9c3] + MbedTLS_jll v2.28.2+0
[14a3606d] + MozillaCACerts_jll v2022.10.11
[4536629a] + OpenBLAS_jll v0.3.21+4
[83775a58] + Zlib_jll v1.2.13+0
[8e850b90] + libblastrampoline_jll v5.8.0+0
[8e850ede] + nghttp2_jll v1.48.0+0
[3f19e933] + p7zip_jll v17.4.0+0
Precompiling project...
5 dependencies successfully precompiled in 12 seconds. 20 already precompiled.

julia> using PythonCall
[ Info: Precompiling PythonCall [6099a3de-0909-46bc-b1f4-468b9a2dfc0d]
CondaPkg Found dependencies: /Users/x/.julia/packages/PythonCall/qTEA1/CondaPkg.toml
CondaPkg Found dependencies: /Users/x/.julia/packages/SymPyPythonCall/yNd8x/CondaPkg.toml
CondaPkg Resolving changes
+ python
+ sympy
CondaPkg Creating environment
│ /Users/x/.julia/artifacts/5767a45b62528e0be4c40dbae502ad3e132f1d62/bin/micromamba
│ -r /Users/x/.julia/scratchspaces/0b3b1443-0f03-428d-bdfb-f27f9c1191ea/root
│ create
│ -y
│ -p /var/folders/hc/fn82kz1j5vl8w7lwd4l079y80000gn/T/jl_NIT4tY/.CondaPkg/env
│ --override-channels
│ --no-channel-priority
│ python[version='>=3.7,<4',channel='conda-forge',build='*cpython*']
│ python[version='*']
│ sympy[version='*']
└ -c conda-forge
conda-forge/noarch 12.5MB @ 3.0MB/s 4.2s
conda-forge/osx-arm64 6.8MB @ 1.1MB/s 6.4s

Transaction

Prefix: /private/var/folders/hc/fn82kz1j5vl8w7lwd4l079y80000gn/T/jl_NIT4tY/.CondaPkg/env

Updating specs:

- conda-forge::python[version='>=3.7,<4',build=*cpython*]
- python=*
- sympy=*

Package Version Build Channel Size
────────────────────────────────────────────────────────────────────────────
Install:
────────────────────────────────────────────────────────────────────────────

+ xz 5.2.6 h57fd34a_0 conda-forge Cached
+ libexpat 2.5.0 hb7217d7_1 conda-forge Cached
+ ncurses 6.4 h7ea286d_0 conda-forge Cached
+ libffi 3.4.2 h3422bc3_5 conda-forge Cached
+ libzlib 1.2.13 h53f4e23_5 conda-forge Cached
+ ca-certificates 2023.7.22 hf0a4a13_0 conda-forge Cached
+ python_abi 3.11 4_cp311 conda-forge Cached
+ libcxx 16.0.6 h4653b0c_0 conda-forge Cached
+ bzip2 1.0.8 h3422bc3_4 conda-forge Cached
+ readline 8.2 h92ec313_1 conda-forge Cached
+ libsqlite 3.43.0 hb31c410_0 conda-forge Cached
+ tk 8.6.12 he1e0b03_0 conda-forge Cached
+ openssl 3.1.3 h53f4e23_0 conda-forge Cached
+ gmp 6.2.1 h9f76cd9_0 conda-forge Cached
+ mpfr 4.2.0 he09a6ba_0 conda-forge Cached
+ mpc 1.3.1 h91ba8db_0 conda-forge Cached
+ tzdata 2023c h71feb2d_0 conda-forge Cached
+ python 3.11.5 h47c9636_0_cpython conda-forge Cached
+ wheel 0.41.2 pyhd8ed1ab_0 conda-forge Cached
+ setuptools 68.2.2 pyhd8ed1ab_0 conda-forge Cached
+ pip 23.2.1 pyhd8ed1ab_0 conda-forge Cached
+ mpmath 1.3.0 pyhd8ed1ab_0 conda-forge Cached
+ gmpy2 2.1.2 py311h2ba9262_1 conda-forge Cached
+ sympy 1.12 pypyh9d50eac_103 conda-forge Cached

Summary:

Install: 24 packages

Total download: 0 B

────────────────────────────────────────────────────────────────────────────

Transaction starting
Linking xz-5.2.6-h57fd34a_0
Linking libexpat-2.5.0-hb7217d7_1
Linking ncurses-6.4-h7ea286d_0
Linking libffi-3.4.2-h3422bc3_5
Linking libzlib-1.2.13-h53f4e23_5
Linking ca-certificates-2023.7.22-hf0a4a13_0
Linking python_abi-3.11-4_cp311
Linking libcxx-16.0.6-h4653b0c_0
Linking bzip2-1.0.8-h3422bc3_4
Linking readline-8.2-h92ec313_1
Linking libsqlite-3.43.0-hb31c410_0
Linking tk-8.6.12-he1e0b03_0
Linking openssl-3.1.3-h53f4e23_0
Linking gmp-6.2.1-h9f76cd9_0
Linking mpfr-4.2.0-he09a6ba_0
Linking mpc-1.3.1-h91ba8db_0
Linking tzdata-2023c-h71feb2d_0
Linking python-3.11.5-h47c9636_0_cpython
Linking wheel-0.41.2-pyhd8ed1ab_0
Linking setuptools-68.2.2-pyhd8ed1ab_0
Linking pip-23.2.1-pyhd8ed1ab_0
Linking mpmath-1.3.0-pyhd8ed1ab_0
Linking gmpy2-2.1.2-py311h2ba9262_1
Linking sympy-1.12-pypyh9d50eac_103

Transaction finished

To activate this environment, use:

micromamba activate /private/var/folders/hc/fn82kz1j5vl8w7lwd4l079y80000gn/T/jl_NIT4tY/.CondaPkg/env

Or to execute a single command in this environment, use:

micromamba run -p /private/var/folders/hc/fn82kz1j5vl8w7lwd4l079y80000gn/T/jl_NIT4tY/.CondaPkg/env mycommand

julia> pyexec("x = 1", Main)

julia> pyeval("x", Main)
Python: 1

julia> @pyexec "y = 2"

julia> @pyeval "y"
ERROR: Python: NameError: name 'y' is not defined
Python stacktrace:
[1]
@ REPL[7]:1:1
Stacktrace:
[1] pythrow()
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/err.jl:94
[2] errcheck
@ ~/.julia/packages/PythonCall/qTEA1/src/err.jl:10 [inlined]
[3] pycallargs(f::Py, args::Py)
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/abstract/object.jl:210
[4] pycall(::Py, ::Py, ::Vararg{Py}; kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/abstract/object.jl:228
[5] pycall
@ ~/.julia/packages/PythonCall/qTEA1/src/abstract/object.jl:218 [inlined]
[6] #_#11
@ ~/.julia/packages/PythonCall/qTEA1/src/Py.jl:341 [inlined]
[7] Py
@ ~/.julia/packages/PythonCall/qTEA1/src/Py.jl:341 [inlined]
[8] pyeval(::Type{Py}, code::Py, globals::Module, locals::Tuple{})
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/concrete/code.jl:43
[9] top-level scope
@ ~/.julia/packages/PythonCall/qTEA1/src/concrete/code.jl:146

julia> @pyexec "y"
ERROR: Python: NameError: name 'y' is not defined
Python stacktrace:
[1]
@ REPL[8]:1:1
Stacktrace:
[1] pythrow()
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/err.jl:94
[2] errcheck
@ ~/.julia/packages/PythonCall/qTEA1/src/err.jl:10 [inlined]
[3] pycallargs(f::Py, args::Py)
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/abstract/object.jl:210
[4] pycall(::Py, ::Py, ::Vararg{Py}; kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/abstract/object.jl:228
[5] pycall
@ ~/.julia/packages/PythonCall/qTEA1/src/abstract/object.jl:218 [inlined]
[6] #_#11
@ ~/.julia/packages/PythonCall/qTEA1/src/Py.jl:341 [inlined]
[7] Py
@ ~/.julia/packages/PythonCall/qTEA1/src/Py.jl:341 [inlined]
[8] pyexec(::Type{Nothing}, code::Py, globals::Module, locals::Tuple{})
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/concrete/code.jl:98
[9] top-level scope
@ ~/.julia/packages/PythonCall/qTEA1/src/concrete/code.jl:146

julia> @pyexec """
def f(x):
return x + 1
"""

julia> @pyeval "f(1)"
ERROR: Python: NameError: name 'f' is not defined
Python stacktrace:
[1]
@ REPL[10]:1:1
Stacktrace:
[1] pythrow()
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/err.jl:94
[2] errcheck
@ ~/.julia/packages/PythonCall/qTEA1/src/err.jl:10 [inlined]
[3] pycallargs(f::Py, args::Py)
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/abstract/object.jl:210
[4] pycall(::Py, ::Py, ::Vararg{Py}; kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/abstract/object.jl:228
[5] pycall
@ ~/.julia/packages/PythonCall/qTEA1/src/abstract/object.jl:218 [inlined]
[6] #_#11
@ ~/.julia/packages/PythonCall/qTEA1/src/Py.jl:341 [inlined]
[7] Py
@ ~/.julia/packages/PythonCall/qTEA1/src/Py.jl:341 [inlined]
[8] pyeval(::Type{Py}, code::Py, globals::Module, locals::Tuple{})
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/concrete/code.jl:43
[9] top-level scope
@ ~/.julia/packages/PythonCall/qTEA1/src/concrete/code.jl:146

julia> pyeval("f(1)", Main)
ERROR: Python: NameError: name 'f' is not defined
Python stacktrace:
[1]
@ :1
Stacktrace:
[1] pythrow()
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/err.jl:94
[2] errcheck
@ ~/.julia/packages/PythonCall/qTEA1/src/err.jl:10 [inlined]
[3] pycallargs(f::Py, args::Py)
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/abstract/object.jl:210
[4] pycall(::Py, ::String, ::Vararg{Any}; kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/abstract/object.jl:228
[5] pycall
@ ~/.julia/packages/PythonCall/qTEA1/src/abstract/object.jl:218 [inlined]
[6] #_#11
@ ~/.julia/packages/PythonCall/qTEA1/src/Py.jl:341 [inlined]
[7] Py
@ ~/.julia/packages/PythonCall/qTEA1/src/Py.jl:341 [inlined]
[8] pyeval
@ ~/.julia/packages/PythonCall/qTEA1/src/concrete/code.jl:43 [inlined]
[9] pyeval
@ ~/.julia/packages/PythonCall/qTEA1/src/concrete/code.jl:47 [inlined]
[10] pyeval(code::String, globals::Module)
@ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/concrete/code.jl:47
[11] top-level scope
@ REPL[11]:1

julia> @pyeval "x"
Python: 1

(jl_NIT4tY) pkg> st -m
Status `/private/var/folders/hc/fn82kz1j5vl8w7lwd4l079y80000gn/T/jl_NIT4tY/Manifest.toml`
[992eb4ea] CondaPkg v0.2.20
[9a962f9c] DataAPI v1.15.0
[e2d170a0] DataValueInterfaces v1.0.0
[82899510] IteratorInterfaceExtensions v1.0.0
[692b3bcd] JLLWrappers v1.5.0
[0f8b85d8] JSON3 v1.13.2
[1914dd2f] MacroTools v0.5.11
[0b3b1443] MicroMamba v0.1.14
[bac558e1] OrderedCollections v1.6.2
[69de0a69] Parsers v2.7.2
[fa939f87] Pidfile v1.3.0
[aea7be01] PrecompileTools v1.2.0
[21216c6a] Preferences v1.4.1
[6099a3de] PythonCall v0.9.14
[ae029012] Requires v1.3.0
[6c6a2e73] Scratch v1.2.0
[856f2bd8] StructTypes v1.10.0
[3783bdb8] TableTraits v1.0.1
[bd369af6] Tables v1.11.0
[e17b2a0c] UnsafePointers v1.0.0
[f8abcde7] micromamba_jll v1.4.9+0
[0dad84c5] ArgTools v1.1.1
[56f22d72] Artifacts
[2a0f44e3] Base64
[ade2ca70] Dates
[f43a241f] Downloads v1.6.0
[7b1f6079] FileWatching
[b77e0a4c] InteractiveUtils
[4af54fe1] LazyArtifacts
[b27032c2] LibCURL v0.6.3
[76f85450] LibGit2
[8f399da3] Libdl
[37e2e46d] LinearAlgebra
[56ddb016] Logging
[d6f4376e] Markdown
[a63ad114] Mmap
[ca575930] NetworkOptions v1.2.0
[44cfe95a] Pkg v1.9.2
[de0858da] Printf
[3fa0cd96] REPL
[9a3f8284] Random
[ea8e919c] SHA v0.7.0
[9e88b42a] Serialization
[6462fe0b] Sockets
[fa267f1f] TOML v1.0.3
[a4e569a6] Tar v1.10.0
[8dfed614] Test
[cf7118a7] UUIDs
[4ec0a83e] Unicode
[e66e0078] CompilerSupportLibraries_jll v1.0.5+0
[deac9b47] LibCURL_jll v7.84.0+0
[29816b5a] LibSSH2_jll v1.10.2+0
[c8ffd9c3] MbedTLS_jll v2.28.2+0
[14a3606d] MozillaCACerts_jll v2022.10.11
[4536629a] OpenBLAS_jll v0.3.21+4
[83775a58] Zlib_jll v1.2.13+0
[8e850b90] libblastrampoline_jll v5.8.0+0
[8e850ede] nghttp2_jll v1.48.0+0
[3f19e933] p7zip_jll v17.4.0+0

julia> versioninfo()
Julia Version 1.9.3
Commit bed2cd540a1 (2023-08-24 14:43 UTC)
Build Info:
Official https://julialang.org/ release
Platform Info:
OS: macOS (arm64-apple-darwin22.4.0)
CPU: 8 × Apple M2
WORD_SIZE: 64
LIBM: libopenlibm
LLVM: libLLVM-14.0.6 (ORCJIT, apple-m1)
Threads: 1 on 4 virtual cores
Environment:
JULIA_EDITOR = code
```