TypeError: len() of unsized object

[wwl62]

Type: Bug

Behaviour

Expected vs. Actual

XXX

Steps to reproduce:

1. XXX

Diagnostic data

• Jupyter extension version: 2025.9.1
• Python extension version: 2026.4.0
• .NET Install Tool for Extension Authors extension version: Not installed
• Python runtime version: 3.12.3 | packaged by conda-forge | (main, Apr 15 2024, 18:20:11) [MSC v.1938 64 bit (AMD64)]
• Python package dependencies:

{
  "installed": {
    "pandas": "2.2.2",
    "numpy": "1.26.4",
    "torch": "2.7.1+cu118"
  },
  "required": {
    "pandas": "1.2.0"
  },
  "unsatisfied": [],
  "failedChecks": [
    "polars",
    "pyarrow",
    "pyspark",
    "tensorflow",
    "xarray"
  ]
}

• Entrypoint: JupyterDataViewer
• Active mode: dataWrangler

Extension version: 1.24.2
VS Code version: Code 1.127.0 (4fe60c8b1cdac1c4c174f2fb180d0d758272d713, 2026-06-30T10:52:33+02:00)
OS version: Windows_NT x64 10.0.26200
Modes:

System Info

Item	Value
CPUs	AMD Ryzen 7 7840H with Radeon 780M Graphics (16 x 3793)
GPU Status	2d_canvas: enabled GPU0: VENDOR= 0x10de, DEVICE=0x28e0 [NVIDIA GeForce RTX 4060 Laptop GPU], DRIVER_VENDOR=NVIDIA, DRIVER_VERSION=32.0.15.6094 ACTIVE GPU1: VENDOR= 0x1002, DEVICE=0x15bf [AMD Radeon 780M Graphics], DRIVER_VERSION=31.0.22060.7002 GPU2: VENDOR= 0x1002, DEVICE=0x15bf [AMD Radeon 780M Graphics], DRIVER_VERSION=31.0.22060.7002 GPU3: VENDOR= 0x1002, DEVICE=0x15bf [AMD Radeon 780M Graphics], DRIVER_VERSION=31.0.22060.7002 GPU4: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.26100.8521 Machine model name: Machine model version: direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: disabled_off trees_in_viz: disabled_off video_decode: enabled video_encode: enabled webgl: enabled webgpu: enabled webnn: disabled_off
Load (avg)	undefined
Memory (System)	15.19GB (5.11GB free)
Process Argv	F:\博\小论文\优化\MORL\code --crash-reporter-id 45de6ec6-f83c-4854-972b-e76cccd111de
Screen Reader	no
VM	0%

A/B Experiments

vsliv368cf:30146710
vswsl492:30256859
pythonvspyt551:31249599
binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
pythonrdcb7:31342333
6518g693:31463988
aj953862:31281341
6abeh943:31336334
envsdeactivate2:31538737
cloudbuttont:31379625
3efgi100_wstrepl:31403338
ec5jj548:31422691
cp_cls_t_966_ss:31526232
4je02754:31466945
8hhj4413:31478653
cp_cls_c_1081:31454833
conptydll_true:31498968
ia-use-proxy-models-svc:31452481
core-renderer-profiling-on:31440367
e9c30283:31461165
test_treatment2:31471001
46204921:31447328
idci7584:31464702
e3e4d672:31494082
ei9d7968:31496641
nes-extended-on:31455476
chat:31457767
8hig5102:31480529
89g7j272:31518289
7e187181:31503455
i2gc6536:31499202
52612955:31516516
githubstableflight:31469463
ghj88844:31499326
h08i8180:31475369
ddid_c:31478207
hmra_i5g22:31518061
7df3h592:31512476
cp_cls_t_1082:31535311
logging_enabled_new:31498466
j0d79568:31499440
jb_cp_cls_t_632:31543129
56dj4588:31512888
32d76977:31512328
ha629193:31508444
cdk-lw-on:31524445
f9bf7985:31543584
2cfga817_c:31522397
a1ije391_t:31540920
g4a0e106:31529594
8hfba999:31537718
jbcp_cls_pctr_t:31531130
61138546:31518536
cp_intellij_t_nes:31533504
jf4hg949:31526829
nes-curr-leftover-1500:31538366
h561g132:31533256
sessions_3:31532893
h7dd7680:31543284
ihg5j128:31534457
9gg7f176:31542112