tzl
tzl
PostsComments
MModular
Created by tzl on 5/14/2024 in #questions
Why is this in-place operation not modifying the Python object in-place?
Raised: https://github.com/modularml/mojo/issues/2653
8 replies
MModular
Created by tzl on 5/14/2024 in #questions
Why is this in-place operation not modifying the Python object in-place?
What I was expressing in the original post was more similar to when PythonObject is a list. This would mutate the Python object internally. 
from python import Python

def do_py_stuff(li: PythonObject) -> PythonObject:
    li.append(1)
    print("inside function:\n", li)

    return li


fn main() raises:
    var li = Python.list()
    print(li)

    print("do_py_stuff:")
    do_py_stuff(li)
    print("outside function:\n", li)
from python import Python

def do_py_stuff(li: PythonObject) -> PythonObject:
    li.append(1)
    print("inside function:\n", li)

    return li


fn main() raises:
    var li = Python.list()
    print(li)

    print("do_py_stuff:")
    do_py_stuff(li)
    print("outside function:\n", li)
 mojo do_numpy_stuff.mojo
[]
do_py_stuff:
inside function:
 [1]
outside function:
 [1]
 mojo do_numpy_stuff.mojo
[]
do_py_stuff:
inside function:
 [1]
outside function:
 [1]
8 replies
MModular
Created by tzl on 5/14/2024 in #questions
Why is this in-place operation not modifying the Python object in-place?
I understand with inout it would be mutated. But inout is when regarding a Mojo variable, one could reassign this variable (lvalue) to anything of the same type: 
from python import Python

def do_numpy_stuff(inout ar: PythonObject) -> PythonObject:
    ar = Python.list()
    print("inside function:\n", ar)

    return ar


fn main() raises:
    var np = Python.import_module("numpy")
    var ar = np.arange(15).reshape(3, 5)
    print(ar)

    print("do_numpy_stuff:")
    do_numpy_stuff(ar)
    print("outside function:\n", ar)
from python import Python

def do_numpy_stuff(inout ar: PythonObject) -> PythonObject:
    ar = Python.list()
    print("inside function:\n", ar)

    return ar


fn main() raises:
    var np = Python.import_module("numpy")
    var ar = np.arange(15).reshape(3, 5)
    print(ar)

    print("do_numpy_stuff:")
    do_numpy_stuff(ar)
    print("outside function:\n", ar)
prints out 
> mojo do_numpy_stuff.mojo
[[ 0  1  2  3  4]
 [ 5  6  7  8  9]
 [10 11 12 13 14]]
do_numpy_stuff:
inside function:
 []
outside function:
 []
> mojo do_numpy_stuff.mojo
[[ 0  1  2  3  4]
 [ 5  6  7  8  9]
 [10 11 12 13 14]]
do_numpy_stuff:
inside function:
 []
outside function:
 []
Any PythonObject would do. This is a separate point from what I was trying to show up there in the orignal post.
8 replies