Unwanted dependency on Redis and SQLAlchemy

[scranen]

It seems that this PR, intended to improve documentation, had the side effect of making it impossible to import anything from the datastore package unless you have Redis and SQLAlchemy installed.

Versions

• Python: any
• OS: any
• Pymodbus: 3.1.2
• Modbus Hardware (if used): n/a

Pymodbus Specific

• Server: tcp/rtu/ascii - sync/async
• Client: tcp/rtu/ascii - sync/async

Description

I'm trying to import some classes from the datastore package to set up a mock. This worked before, but with the latest release of PyModbus this results in an error.

Code and Logs

from pymodbus.datastore import (
    ModbusSlaveContext, 
    ModbusServerContext,
    ModbusSparseDataBlock
)

Results in:

Traceback (most recent call last):
  File "/Users/scranen/Repos/fca/devices/test/mock_ptl_controller.py", line 6, in <module>
    from pymodbus.datastore import (
  File "/Users/scranen/.local/share/virtualenvs/devices-2hMeqm5U/lib/python3.10/site-packages/pymodbus/datastore/__init__.py", line 3, in <module>
    from pymodbus.datastore.database.redis_datastore import RedisSlaveContext
  File "/Users/scranen/.local/share/virtualenvs/devices-2hMeqm5U/lib/python3.10/site-packages/pymodbus/datastore/database/__init__.py", line 2, in <module>
    from pymodbus.datastore.database.redis_datastore import RedisSlaveContext
  File "/Users/scranen/.local/share/virtualenvs/devices-2hMeqm5U/lib/python3.10/site-packages/pymodbus/datastore/database/redis_datastore.py", line 5, in <module>
    import redis
ModuleNotFoundError: No module named 'redis'

[janiversen]

Solved on dev and will be released as a patch fix very soon.

[IgorVDubov]

the same thing in
/pymodbus/server/init.py
...
from pymodbus.server.simulator.http_server import ModbusSimulatorServer
breaks with import error if ModbusSimulatorServer not installed

[janiversen]

??? how do you make an installation without the ModbuSImulatorServer, that is an integrated part of pymodbus.

[IgorVDubov]

Sorry, my mistake,
when commenting described above datastore imports, I commented this in error:
"from pymodbus.datastore.simulator import ModbusSimulatorContext"
and take import error at /pymodbus/server/init.py
Yes, all works fine, sorry for worryng, thanks for your product