No module named 'rlp.codec'

• py-evm Version: xxx
• trinity Version:eth-0.2.0a31
• OS: osx
• Python Version (python --version): Python 3.6.4 :: Anaconda, Inc.
• Environment (output of pip freeze):

alabaster==0.7.11 apipkg==1.5 appnope==0.1.0 argh==0.26.2 asn1crypto==0.24.0 async-lru==0.1.0 asyncio-cancel-token==0.1.0a2 atomicwrites==1.2.1 attrdict==2.0.0 attrs==18.1.0 Babel==2.6.0 backcall==0.1.0 bloom-filter==1.3 bumpversion==0.5.3 cachetools==2.1.0 certifi==2018.8.24 cffi==1.11.5 chardet==3.0.4 coincurve==8.0.2 colorama==0.3.9 coverage==4.5.1 cryptography==2.3.1 cytoolz==0.9.0.1 decorator==4.3.0 docopt==0.6.2 docutils==0.14 eth-abi==1.2.0 eth-account==0.2.3 eth-bloom==1.0.0 eth-hash==0.1.4 eth-keyfile==0.5.1 eth-keys==0.2.0b3 eth-rlp==0.1.2 eth-typing==1.3.0 eth-utils==1.2.1 execnet==1.5.0 flake8==3.5.0 hexbytes==0.1.0 hypothesis==3.69.5 idna==2.7 imagesize==1.0.0 ipython==6.5.0 ipython-genutils==0.2.0 jedi==0.12.1 Jinja2==2.10 lahja==0.6.1 lru-dict==1.1.6 lxml==4.2.4 MarkupSafe==1.0 mccabe==0.6.1 more-itertools==4.3.0 mypy==0.620 netdisco==2.0.0 netifaces==0.10.7 packaging==17.1 parsimonious==0.8.0 parso==0.3.1 pathtools==0.1.2 pexpect==4.6.0 pickleshare==0.7.4 pkginfo==1.4.2 pluggy==0.7.1 plyvel==1.0.5 prompt-toolkit==1.0.15 ptyprocess==0.6.0 py==1.6.0 py-ecc==1.4.3 -e [e-mail]:ethereum/py-evm.git@632bf8a710d8bfc2f20e7d25f9976f9bcd25ff51#egg=py_evm pycodestyle==2.3.1 pycparser==2.18 pycryptodome==3.6.6 pyethash==0.1.27 pyflakes==1.6.0 Pygments==2.2.0 pyparsing==2.2.0 pysha3==1.0.2 pytest==3.6.4 pytest-asyncio==0.9.0 pytest-asyncio-network-simulator==0.1.0a2 pytest-cov==2.5.1 pytest-watch==4.2.0 pytest-xdist==1.18.1 python-dateutil==2.7.3 pytz==2018.5 PyYAML==3.13 requests==2.19.1 requests-toolbelt==0.8.0 rlp==1.0.2 simplegeneric==0.8.1 six==1.11.0 snowballstemmer==1.2.1 Sphinx==1.7.8 sphinx-rtd-theme==0.4.1 sphinxcontrib-asyncio==0.2.0 sphinxcontrib-websupport==1.1.0 toolz==0.9.0 tox==2.7.0 tqdm==4.25.0 traitlets==4.3.2 trie==1.3.8 twine==1.11.0 typed-ast==1.1.0 uPnPClient==0.0.8 urllib3==1.23 virtualenv==16.0.0 watchdog==0.9.0 wcwidth==0.1.7 web3==4.4.1 websockets==5.0.1 zeroconf==0.20.0

What is wrong?

i want to read and run the trinity code, but the always show error

No module named 'rlp.codec'

There is a rlp folder under the trinity directory how import rlp from site-packages not the rlp folder?

(py-evm-VXvi0lYJ) ➜  py-evm git:(master) ✗ python trinity/main.py      
Traceback (most recent call last):
  File "trinity/main.py", line 18, in <module>
    from eth.chains.mainnet import (
  File "/Users/gaojin/Documents/GitHub/py-evm/eth/__init__.py", line 14, in <module>
    from eth.chains import (  # noqa: F401
  File "/Users/gaojin/Documents/GitHub/py-evm/eth/chains/__init__.py", line 1, in <module>
    from .base import (  # noqa: F401
  File "/Users/gaojin/Documents/GitHub/py-evm/eth/chains/base.py", line 46, in <module>
    from eth.db.chain import (
  File "/Users/gaojin/Documents/GitHub/py-evm/eth/db/chain.py", line 18, in <module>
    from trie import (
  File "/Users/gaojin/.local/share/virtualenvs/py-evm-VXvi0lYJ/lib/python3.6/site-packages/trie/__init__.py", line 7, in <module>
    from .hexary import (  # noqa: F401
  File "/Users/gaojin/.local/share/virtualenvs/py-evm-VXvi0lYJ/lib/python3.6/site-packages/trie/hexary.py", line 5, in <module>
    from rlp.codec import encode_raw
ModuleNotFoundError: No module named 'rlp.codec'

[jin10086]

Thank you very much, this is very helpful to me.

[cburgdorf]

Ah, understood! No, running python trinity/main.py doesn’t work for me either. I’m also running into:

$ python trinity/main.py 
Traceback (most recent call last):
  File "trinity/main.py", line 17, in <module>
    from eth.chains.mainnet import (
  File "/home/cburgdorf/Documents/hacking/ef/py-evm/eth/__init__.py", line 14, in <module>
    from eth.chains import (  # noqa: F401
  File "/home/cburgdorf/Documents/hacking/ef/py-evm/eth/chains/__init__.py", line 1, in <module>
    from .base import (  # noqa: F401
  File "/home/cburgdorf/Documents/hacking/ef/py-evm/eth/chains/base.py", line 46, in <module>
    from eth.db.chain import (
  File "/home/cburgdorf/Documents/hacking/ef/py-evm/eth/db/chain.py", line 18, in <module>
    from trie import (
  File "/home/cburgdorf/Documents/hacking/ef/py-evm/venv3/lib/python3.6/site-packages/trie/__init__.py", line 7, in <module>
    from .hexary import (  # noqa: F401
  File "/home/cburgdorf/Documents/hacking/ef/py-evm/venv3/lib/python3.6/site-packages/trie/hexary.py", line 5, in <module>
    from rlp.codec import encode_raw
ModuleNotFoundError: No module named 'rlp.codec'

Btw, notice that this kind of launch would also need this to be added:

if __name__ == "__main__":
    main()

However, I don’t know where this error comes from and I know that this kind of launch used to work a couple of months back. However, if you really want to start trinity using python <something> instead of just launching it through the trinity command, you can do so by running python -m trinity.main which will give you a bunch of warnings but beside that will launch trinity just fine.

$ python -m trinity.main
/usr/lib/python3.6/runpy.py:125: RuntimeWarning: 'trinity.main' found in sys.modules after import of package 'trinity', but prior to execution of 'trinity.main'; this may result in unpredictable behaviour
  warn(RuntimeWarning(msg))
    INFO  09-18 11:30:08        main  
      ______     _       _ __       
     /_  __/____(_)___  (_) /___  __
      / / / ___/ / __ \/ / __/ / / /
     / / / /  / / / / / / /_/ /_/ / 
    /_/ /_/  /_/_/ /_/_/\__/\__, /  
                           /____/   
    INFO  09-18 11:30:08        main  Trinity/eth-0.2.0a32/linux/cpython3.6.5
    INFO  09-18 11:30:08        main  Trinity DEBUG log file is created at /home/cburgdorf/.local/share/trinity/mainnet/logs/trinity.log
    INFO  09-18 11:30:08        main  Started DB server process (pid=9435)
/usr/lib/python3.6/runpy.py:125: RuntimeWarning: 'trinity.main' found in sys.modules after import of package 'trinity', but prior to execution of 'trinity.main'; this may result in unpredictable behaviour
  warn(RuntimeWarning(msg))
    INFO  09-18 11:30:08        main  Started networking process (pid=9439)
    INFO  09-18 11:30:08  plugin_manager  Plugin started: JSON-RPC Server
/usr/lib/python3.6/runpy.py:125: RuntimeWarning: 'trinity.main' found in sys.modules after import of package 'trinity', but prior to execution of 'trinity.main'; this may result in unpredictable behaviour
  warn(RuntimeWarning(msg))
/usr/lib/python3.6/runpy.py:125: RuntimeWarning: 'trinity.main' found in sys.modules after import of package 'trinity', but prior to execution of 'trinity.main'; this may result in unpredictable behaviour
  warn(RuntimeWarning(msg))
    INFO  09-18 11:30:09      plugin  JSON-RPC Server started
    INFO  09-18 11:30:09         ipc  IPC started at: /home/cburgdorf/.local/share/trinity/mainnet/jsonrpc.ipc
    INFO  09-18 11:30:09      server  Running server...
    INFO  09-18 11:30:09         nat  Setting up NAT portmap...
/usr/lib/python3.6/runpy.py:125: RuntimeWarning: 'trinity.main' found in sys.modules after import of package 'trinity', but prior to execution of 'trinity.main'; this may result in unpredictable behaviour
  warn(RuntimeWarning(msg))

I’m far from being a Python expert so I can’t explain to you the details of why things are the way they are but I hope this gives you the right pointers to address your problem.