Set up a clean environment

Many things can cause a broken environment. You might be on an unsupported version of Python. Another package might be installed that has a name or version conflict. Often, the best way to guarantee a correct environment is with virtualenv, like:

# Install pip if it is not available:
$ which pip || curl | python

# Install virtualenv if it is not available:
$ which virtualenv || pip install --upgrade virtualenv

# *If* the above command displays an error, you can try installing as root:
$ sudo pip install virtualenv

# Create a virtual environment:
$ virtualenv -p python3 ~/.venv-py3

# Activate your new virtual environment:
$ source ~/.venv-py3/bin/activate

# With virtualenv active, make sure you have the latest packaging tools
$ pip install --upgrade pip setuptools

# Now we can install
$ pip install --upgrade web3


Remember that each new terminal session requires you to reactivate your virtualenv, like: $ source ~/.venv-py3/bin/activate

How do I use my MetaMask accounts from

Often you don’t need to do this, just make a new account in, and transfer funds from your MetaMask account into it. But if you must…

Export your private key from MetaMask, and use the local private key tools in to sign and send transactions.

See how to export your private key and Working with Local Private Keys.

How do I get ether for my test network?

Test networks usually have something called a “faucet” to help get test ether to people who want to use it. The faucet simply sends you test ether when you visit a web page, or ping a chat bot, etc.

Each test network has its own version of test ether, so each one must maintain its own faucet. If you’re not sure which test network to use, see Which network should I connect to?

Faucet mechanisms tend to come and go, so if any information here is out of date, try the Ethereum Stackexchange. Here are some links to testnet ether instructions (in no particular order):