· poetry python dagster til

Poetry/Dagster: ImportError: cannot import name 'appengine' from 'requests.packages.urllib3.contrib'

I’m taking some tentative steps into the world of batch data pipelines and I’ve been following Dagster’s DuckDB tutorial when I ran into a dependency issue that I had to work around. In this blog post, I’ll share the steps that I took in case you run into the same issue.

I’m using the Poetry dependency management tool, but I think you’d get the same issue even if you used pip directly. We’re going to start by adding the following dependencies:

poetry add dagster duckdb dagster-duckdb dagster-duckdb-pandas dagster-webserver

And then we’ll create a file called dagster_iris.py that defines one asset, which ingests the Iris dataset into DuckDB.

from dagster_duckdb import DuckDBResource
from dagster import Definitions, asset

def iris_dataset(duckdb: DuckDBResource) -> None:
    iris_df = pd.read_csv(

    with duckdb.get_connection() as conn:
        conn.execute("CREATE TABLE iris.iris_dataset AS SELECT * FROM iris_df")

defs = Definitions(
        "duckdb": DuckDBResource(
            database="/tmp/iris.duckdb",  # required

Next, we’re going to launch Dagster’s UI so that we can materialise this asset:

poetry run dagster dev -f dagster_iris.py

But we immediately run into this error:

Traceback (most recent call last):
  File "/Users/markhneedham/Library/Caches/pypoetry/virtualenvs/tmp-Ef4UpWP3-py3.11/lib/python3.11/site-packages/requests_toolbelt/_compat.py", line 48, in <module>
    from requests.packages.urllib3.contrib import appengine as gaecontrib
ImportError: cannot import name 'appengine' from 'requests.packages.urllib3.contrib' (/Users/markhneedham/Library/Caches/pypoetry/virtualenvs/tmp-Ef4UpWP3-py3.11/lib/python3.11/site-packages/urllib3/contrib/__init__.py)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "/Users/markhneedham/Library/Caches/pypoetry/virtualenvs/tmp-Ef4UpWP3-py3.11/lib/python3.11/site-packages/dagster_webserver/__main__.py", line 1, in <module>
    from .cli import main  # pragma: no cover
  File "/Users/markhneedham/Library/Caches/pypoetry/virtualenvs/tmp-Ef4UpWP3-py3.11/lib/python3.11/site-packages/dagster_webserver/cli.py", line 28, in <module>
    from .app import create_app_from_workspace_process_context
  File "/Users/markhneedham/Library/Caches/pypoetry/virtualenvs/tmp-Ef4UpWP3-py3.11/lib/python3.11/site-packages/dagster_webserver/app.py", line 9, in <module>
    from .webserver import DagsterWebserver
  File "/Users/markhneedham/Library/Caches/pypoetry/virtualenvs/tmp-Ef4UpWP3-py3.11/lib/python3.11/site-packages/dagster_webserver/webserver.py", line 17, in <module>
    from dagster_graphql import __version__ as dagster_graphql_version
  File "/Users/markhneedham/Library/Caches/pypoetry/virtualenvs/tmp-Ef4UpWP3-py3.11/lib/python3.11/site-packages/dagster_graphql/__init__.py", line 3, in <module>
    from .client import (
  File "/Users/markhneedham/Library/Caches/pypoetry/virtualenvs/tmp-Ef4UpWP3-py3.11/lib/python3.11/site-packages/dagster_graphql/client/__init__.py", line 1, in <module>
    from .client import DagsterGraphQLClient as DagsterGraphQLClient
  File "/Users/markhneedham/Library/Caches/pypoetry/virtualenvs/tmp-Ef4UpWP3-py3.11/lib/python3.11/site-packages/dagster_graphql/client/client.py", line 12, in <module>
    from gql.transport.requests import RequestsHTTPTransport
  File "/Users/markhneedham/Library/Caches/pypoetry/virtualenvs/tmp-Ef4UpWP3-py3.11/lib/python3.11/site-packages/gql/transport/requests.py", line 11, in <module>
    from requests_toolbelt.multipart.encoder import MultipartEncoder
  File "/Users/markhneedham/Library/Caches/pypoetry/virtualenvs/tmp-Ef4UpWP3-py3.11/lib/python3.11/site-packages/requests_toolbelt/__init__.py", line 12, in <module>
    from .adapters import SSLAdapter, SourceAddressAdapter
  File "/Users/markhneedham/Library/Caches/pypoetry/virtualenvs/tmp-Ef4UpWP3-py3.11/lib/python3.11/site-packages/requests_toolbelt/adapters/__init__.py", line 12, in <module>
    from .ssl import SSLAdapter
  File "/Users/markhneedham/Library/Caches/pypoetry/virtualenvs/tmp-Ef4UpWP3-py3.11/lib/python3.11/site-packages/requests_toolbelt/adapters/ssl.py", line 16, in <module>
    from .._compat import poolmanager
  File "/Users/markhneedham/Library/Caches/pypoetry/virtualenvs/tmp-Ef4UpWP3-py3.11/lib/python3.11/site-packages/requests_toolbelt/_compat.py", line 50, in <module>
    from urllib3.contrib import appengine as gaecontrib
ImportError: cannot import name 'appengine' from 'urllib3.contrib' (/Users/markhneedham/Library/Caches/pypoetry/virtualenvs/tmp-Ef4UpWP3-py3.11/lib/python3.11/site-packages/urllib3/contrib/__init__.py)
2023-10-09 10:54:31 +0100 - dagster.daemon - INFO - Instance is configured with the following daemons: ['AssetDaemon', 'BackfillDaemon', 'SchedulerDaemon', 'SensorDaemon']
2023-10-09 10:54:35 +0100 - dagster - ERROR - An unexpected exception has occurred
Traceback (most recent call last):
  File "/Users/markhneedham/Library/Caches/pypoetry/virtualenvs/tmp-Ef4UpWP3-py3.11/lib/python3.11/site-packages/dagster/_cli/dev.py", line 176, in dev_command
    raise Exception(
Exception: dagster-webserver process shut down unexpectedly with return code 1
2023-10-09 10:54:35 +0100 - dagster - INFO - Shutting down Dagster services...
2023-10-09 10:54:35 +0100 - dagster.daemon - INFO - Received interrupt, shutting down daemon threads...
2023-10-09 10:54:35 +0100 - dagster.daemon - INFO - Daemon threads shut down.
2023-10-09 10:54:35 +0100 - dagster - INFO - Dagster services shut down.

I came across this thread, which describes a way to fix it.

The cause is that the latest version of requests does not support urllib3 2.0.0. This is fixed in kfp-2.0.0b16 (see PR with the change), so you can either upgrade to that, or create a new image that downgrades urllib.

So I ran the following command:

poetry add urllib3==1.26.15 requests-toolbelt==0.10.1

When I then re-run the dagster dev command, I can happily load the UI:

2023-10-09 10:55:58 +0100 - dagster - INFO - Using temporary directory /private/tmp/tmpswb90dld for storage. This will be removed when dagster dev exits.
2023-10-09 10:55:58 +0100 - dagster - INFO - To persist information across sessions, set the environment variable DAGSTER_HOME to a directory to use.
2023-10-09 10:55:58 +0100 - dagster - INFO - Launching Dagster services...
2023-10-09 10:55:59 +0100 - dagster.daemon - INFO - Instance is configured with the following daemons: ['AssetDaemon', 'BackfillDaemon', 'SchedulerDaemon', 'SensorDaemon']
2023-10-09 10:56:00 +0100 - dagster-webserver - INFO - Serving dagster-webserver on in process 31935
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