Any object with more than two levels is truncated

[MetRonnie]

Type: Bug

Behaviour

Clicking "Copy value" in the variables context menu leads to the presented object being copied as-is, i.e. truncated.

I have tested the JS debugger and it does not exhibit the same behaviour.

Steps to reproduce:

1. Right-click a variable and click "Copy value"
2. Paste somewhere

For example, trying to copy this dictionary:

leads to the clipboard containing this ellipsis

{'hold': {'result': [...]}}

instead of the actual dictionary.

Diagnostic data

launch.json configuration

    "launch": {
        "version": "0.2.0",
        "configurations": [
            {
                "name": "Python: localhost attach",
                "type": "debugpy",
                "request": "attach",
                "justMyCode": false,
                "connect": {
                    "host": "localhost",
                    "port": 6678
                },
                "pathMappings": [
                    {
                        "localRoot": "${workspaceFolder}",
                        "remoteRoot": "${workspaceFolder}"
                    }
                ],
            },
            {
                "name": "Python: Debug Tests",
                "type": "debugpy",
                "request": "launch",
                "program": "${file}",
                "purpose": ["debug-test"],
                "justMyCode": false
              }
        ],
        "compounds": []
    },

Output for Python in the Output panel (View→Output, change the drop-down the upper-right of the Output panel to Python)

N/A

Output for Python Debugger in the Output panel (View→Output, change the drop-down the upper-right of the Output panel to Python Debugger)

N/A

Extension version: 2024.14.0
VS Code version: Code 1.96.2 (fabdb6a30b49f79a7aba0f2ad9df9b399473380f, 2024-12-19T10:22:47.216Z)
OS version: Linux x64 5.14.0-503.21.1.el9_5.x86_64
Modes:

• Python version (& distribution if applicable, e.g. Anaconda): 3.12.6
• Type of virtual environment used (e.g. conda, venv, virtualenv, etc.): Conda
  Details

System Info

Item	Value
CPUs	AMD EPYC 7763 64-Core Processor (4 x 0)
GPU Status	2d_canvas: unavailable_software canvas_oop_rasterization: disabled_off direct_rendering_display_compositor: disabled_off_ok gpu_compositing: disabled_software multiple_raster_threads: enabled_on opengl: disabled_off rasterization: disabled_software raw_draw: disabled_off_ok skia_graphite: disabled_off video_decode: disabled_software video_encode: disabled_software vulkan: disabled_off webgl: unavailable_software webgl2: unavailable_software webgpu: disabled_off webnn: unavailable_software
Load (avg)	2, 1, 2
Memory (System)	15.32GB (6.89GB free)
Process Argv
Screen Reader	no
VM	0%
DESKTOP_SESSION	gnome
XDG_CURRENT_DESKTOP	GNOME
XDG_SESSION_DESKTOP	undefined
XDG_SESSION_TYPE	x11

[rchiodo]

I believe this is by design. Copy in the debugger copies the __repr__ of the variable. It just evals the variable so it ends up with the same thing that the variable view shows.

[rchiodo]

If you want more to be displayed, you have to change the __repr__ for the stuff in the dictionary.

Something like this:

class A():
    def __init__(self):
        self.a = 1
        self.b = 2
        self.c = 3

    def __repr__(self):
        return f"A(a={self.a}, b={self.b}, c={self.c})"

a = A()
dict = {"a": a, "b": list}
print(dict)

[rchiodo]

Can you share your code? It seems weird that you'd get '[...]' in the value for a variable unless it was really deep into iteration. At the first level I don't think it should show just ....

I'm thinking maybe the problem here isn't copying but rather the gathering of the value itself.

[MetRonnie]

The object in question is solely built-ins all the way down. The variable was created by using json.loads(). The full dictionary is like this:

{
    'hold': {
        'result': [{'success': True, 'id': 'a5bf34'}]
    }
}

I can reproduce this with a simple file run in the debugger:

[rchiodo]

It comes down to this constant here:

debugpy/src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_safe_repr.py

Line 33 in 40a471e

maxcollection = (60, 20)

If an object is more than two levels deep (the size of the tuple), it just truncates it. This seems unnecessary to me but changing it could affect the perf of a lot of stuff.

Maybe we'd need a setting to allow this to be controlled by the user.