Sample
pandas 2.3.3: Chained assignment discards mutations while text columns default to object dtype and fallback to python storage without pyarrow
Verified sample for pypi pandas 2.3.3: Chained assignment discards mutations while text columns default to object dtype and fallback to python storage…
sha256:5b203a9e6192c6686bbbd1529e7f7bb5434622bb6f964dc64a9b4f53cc9f5c4e
This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured.
How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people.
MIT-0
Execution evidence
The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.
- Evidence basis
- Signed contract pass
- Verification receipts
- 2
- Signing keys that built it
- 2
Declared environment
python linux x64 python python pip
Verification-run environments
| Environment | Contract | Stages | Run |
|---|---|---|---|
| python 3.12 · linux alpine/x64 · docker ed25519:ac1544ece1e22594 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · python@1 |
2026-08-15 |
| python 3.12 · linux alpine/x64 · docker ed25519:d91480838ac982c9 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · python@1 |
2026-08-18 |
Case
HOW- Goal
- Chained assignment discards mutations while text columns default to object dtype and fallback to python storage without pyarrow
- Packages
- Symbols
-
- pandas.DataFrame
- pandas.Series
- pandas.StringDtype
- pandas.errors.ChainedAssignmentError
- pandas.errors.SettingWithCopyWarning
- pandas.options.mode.copy_on_write
- Environment
- python
- Created
- 2026-08-15T02:48:25Z
Contract
- assert df[df['a'] > 1]['b'] = 99 warns SettingWithCopyWarning and leaves df['b'] unmodified
- assert under copy_on_write df['b'][0] = 99 warns ChainedAssignmentError and leaves df.loc[0, 'b'] unmodified
- assert df['text'].dtype == object and df['text'].dtype != 'string'
- assert pd.Series(['a'], dtype='string').dtype.storage == 'python'
- assert pd.Series(['a'], dtype='string[pyarrow]') raises ImportError when pyarrow is absent
- assert pd.Series(['a', None], dtype='string').iloc[1] is pd.NA
Files
- NOTES.md
- csx.json
- requirements.lock
- requirements.txt
- test/contract.py