using boto3 in a python3 virtual env in AWS Lambda - virtualenv

Question

I am trying to use Python3.4 and boto3 to walk an S3 bucket and publish some file locations to an RDS instance. The part of this effort I am having trouble with is when using boto3. My lambda function looks like the following:
import subprocess
def lambda_handler(event, context):
args = ("venv/bin/python3.4", "run.py")
popen = subprocess.Popen(args, stdout=subprocess.PIPE)
popen.wait()
output = popen.stdout.read()
print(output)
and, in my run.py file I have some lines:
import boto3
s3c = boto3.client('s3')
which cause an exception. The run.py file is not relevant for this question however, so in order make this post more concise, I've found that the cause of this error is generated with executing the lambda function:
import subprocess
def lambda_handler(event, context):
args = ("python3.4", "-c", "import boto3; print(boto3.client('s3'))")
popen = subprocess.Popen(args, stdout=subprocess.PIPE)
popen.wait()
output = popen.stdout.read()
print(output)
My logstream reports the error:
Event Data
START RequestId: 2b65421a-664d-11e6-81db-974c7c09d283 Version: $LATEST
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/var/runtime/boto3/__init__.py", line 79, in client
return _get_default_session().client(*args, **kwargs)
File "/var/runtime/boto3/session.py", line 250, in client
aws_session_token=aws_session_token, config=config)
File "/var/runtime/botocore/session.py", line 818, in create_client
client_config=config, api_version=api_version)
File "/var/runtime/botocore/client.py", line 63, in create_client
cls = self._create_client_class(service_name, service_model)
File "/var/runtime/botocore/client.py", line 85, in _create_client_class
base_classes=bases)
File "/var/runtime/botocore/hooks.py", line 227, in emit
return self._emit(event_name, kwargs)
File "/var/runtime/botocore/hooks.py", line 210, in _emit
response = handler(**kwargs)
File "/var/runtime/boto3/utils.py", line 61, in _handler
module = import_module(module)
File "/var/runtime/boto3/utils.py", line 52, in import_module
__import__(name)
File "/var/runtime/boto3/s3/inject.py", line 13, in <module>
from boto3.s3.transfer import S3Transfer
File "/var/runtime/boto3/s3/transfer.py", line 135, in <module>
from concurrent import futures
File "/var/runtime/concurrent/futures/__init__.py", line 8, in <module>
from concurrent.futures._base import (FIRST_COMPLETED,
File "/var/runtime/concurrent/futures/_base.py", line 357
raise type(self._exception), self._exception, self._traceback
^
SyntaxError: invalid syntax
END RequestId: 2b65421a-664d-11e6-81db-974c7c09d283
REPORT RequestId: 2b65421a-664d-11e6-81db-974c7c09d283 Duration: 2673.45 ms Billed Duration: 2700 ms Memory Size: 1024 MB Max Memory Used: 61 MB
I need to use boto3 downstream of run.py. Any ideas on how to resolve this are much appreciated. Thanks!