Hi guys, I’m trying to run the tap I created with the SDK in Meltano and am getting this error:

meltano invoke tap-spotify
Traceback (most recent call last):
  File "/project/.meltano/extractors/tap-spotify/venv/bin/tap-spotify", line 5, in <module>
    from tap_spotify.tap import TapSpotify
  File "/project/.meltano/extractors/tap-spotify/venv/lib/python3.6/site-packages/tap_spotify/tap.py", line 5, in <module>
    from singer_sdk import Tap, Stream
  File "/project/.meltano/extractors/tap-spotify/venv/lib/python3.6/site-packages/singer_sdk/__init__.py", line 3, in <module>
    from singer_sdk import streams
  File "/project/.meltano/extractors/tap-spotify/venv/lib/python3.6/site-packages/singer_sdk/streams/__init__.py", line 3, in <module>
    from singer_sdk.streams.core import Stream
  File "/project/.meltano/extractors/tap-spotify/venv/lib/python3.6/site-packages/singer_sdk/streams/core.py", line 33, in <module>
    from singer_sdk.helpers._catalog import pop_deselected_record_properties
  File "/project/.meltano/extractors/tap-spotify/venv/lib/python3.6/site-packages/singer_sdk/helpers/_catalog.py", line 9, in <module>
    from singer_sdk.helpers._singer import Catalog, SelectionMask
  File "/project/.meltano/extractors/tap-spotify/venv/lib/python3.6/site-packages/singer_sdk/helpers/_singer.py", line 2, in <module>
    from dataclasses import dataclass, fields
ModuleNotFoundError: No module named 'dataclasses'

I added the plugin using

meltano add --custom extractor tap-spotify

. `meltano.yml`:

version: 1
send_anonymous_usage_stats: true
project_id: 67a2cd63-b43d-498a-9f1c-51a507d983de
plugins:
  extractors:
  - name: tap-spotify
    namespace: tap_spotify
    pip_url:  git+<https://github.com/Matatika/tap-spotify.git>
    executable: tap-spotify
    capabilities:
    - catalog
    - discover
    - properties
    - state
    settings:
    - name: client_id
      kind: password
    - name: client_secret
      kind: password
    - name: refresh_token
      kind: password

The missing

dataclasses

dependency isn’t installed after adding the plugin or running

meltano install extractor tap-spotify

, I’m not that familiar with

poetry

, but the

dataclasses

package seems to be listed as a

dev

dependency(?) in my `poetry.lock`:

[[package]]
name = "dataclasses"
version = "0.8"
description = "A backport of the dataclasses module for Python 3.6"
category = "dev"
optional = false
python-versions = ">=3.6, <3.7"

Hi @Reuben (Matatika)! So,

dataclasses

were added to the stdlib in 3.7, so we have it as a dependency for 3.6.x, but is incorrectly marked as

dev

(fyi @aaronsteers our CI is not catching this cause we're doing

poetry install

which includes dev dependencies but

pip install ...

ignores them). In the meantime can you try to switch to 3.7? 3.6 is approaching EOL anyway

Yeah, I was a bit confused because I remember

dataclasses

being added in 3.7, I just assumed I was using that at first. I’ll report back after I have tested.

Another temporary solution is to add

dataclasses = {version = "*", markers = "python_version < \"3.7\""}

to your tap's

pyproject.toml

in the

[tool.poetry.dependencies]

table

@edgar_ramirez_mondragon Thanks for your help on this - all working fine after upgrading. 👍

Glad that it worked!