import apache_beam metaclass conflict

Question

When I try to import apache beam I get the following error.

>>> import apache_beam
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/toor/pfff/local/lib/python2.7/site-packages/apache_beam/__init__.py", line 78, in <module>
    from apache_beam import io
  File "/home/toor/pfff/local/lib/python2.7/site-packages/apache_beam/io/__init__.py", line 21, in <module>
    ...
    from apitools.base.protorpclite import messages
  File "/home/toor/pfff/local/lib/python2.7/site-packages/apitools/base/protorpclite/messages.py", line 1165, in <module>
    class Field(six.with_metaclass(_FieldMeta, object)):
TypeError: Error when calling the metaclass bases
    metaclass conflict: the metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its bases

I'm working in a new virtual environment in which I have installed apache_beam by installing google-cloud-dataflow with pip as I need the version that is able to run on google cloud platform.

pip install google-cloud-dataflow

I have no idea how to solve this error. For completeness, I'm using python 2.7.12 on bash on ubuntu on Windows. My colleague had the same error when running it on bash on ubuntu on Windows, while directly running on Windows is working fine.

The installed versions of the packages are:

>>> pip freeze
apache-beam==2.1.0
avro==1.8.2
cachetools==2.0.1
certifi==2017.7.27.1
chardet==3.0.4
crcmod==1.7
dill==0.2.6
enum34==1.1.6
funcsigs==1.0.2
future==0.16.0
futures==3.1.1
gapic-google-cloud-pubsub-v1==0.15.4
google-apitools==0.5.11
google-auth==1.1.0
google-auth-httplib2==0.0.2
google-cloud-bigquery==0.25.0
google-cloud-core==0.25.0
google-cloud-dataflow==2.1.0
google-cloud-pubsub==0.26.0
google-gax==0.15.15
googleapis-common-protos==1.5.2
googledatastore==7.0.1
grpc-google-iam-v1==0.11.3
grpcio==1.6.0
httplib2==0.9.2
idna==2.6
mock==2.0.0
oauth2client==3.0.0
pbr==3.1.1
pkg-resources==0.0.0
ply==3.8
proto-google-cloud-datastore-v1==0.90.4
proto-google-cloud-pubsub-v1==0.15.4
protobuf==3.3.0
pyasn1==0.3.5
pyasn1-modules==0.1.4
PyYAML==3.12
requests==2.18.4
rsa==3.4.2
six==1.11.0
urllib3==1.22

Have you tried to install ```pip install apache-beam[gcp]```? — Marcin Zablocki, Sep 19 '17 at 12:59

score 20 · Accepted Answer · answered Sep 19 '17 at 13:09

20

Downgrade six to version 1.10.0

pip install six==1.10.0

answered Sep 19 '17 at 13:09

Anonymous

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A little explanation would certainly be nice. – Jean-François Corbett Sep 19 '17 at 13:19
4

When apache beam is installed, six is also installed when it is not yet installed. It seems like the latest version is installed which is since 2017-09-17 1.11.0 while apache beam is still working with 1.10.0. – Tijl Vandevyvere Sep 19 '17 at 13:22
Can it be mentioned in the setup tools file by apache beam team? So an issue can be raised to ask them to do so (Sorry for such a question, i am newbie) – Anuj Sep 21 '17 at 07:17
apache beam bug for this: https://issues.apache.org/jira/browse/BEAM-2964 – Evan Jones Jan 10 '18 at 22:22

import apache_beam metaclass conflict

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