Web3.py: getCode produces "0x" on smart contract addresses

[gutfeeling]

Version: 4.0.0
Python: 3.5
OS: Linux

What was wrong?

I have Geth (version 1.7.2) node, which was synced using the "fast" mode. When I use the getCode method on smart contract addresses, it always returns "0x". I have verified this with known smart contract addresses like the Iconomi ERC20 token contract address.

I am wondering why this is happening? Is it possible that nodes synced in "fast" mode cannot return the contract bytecode? Or is it a problem with web3py?

Any help is appreciated.

[pipermerriam]

Likely culprits.

• Wrong address (or connected to the wrong chain)
• The node you're connected to isn't fully synced (still in the midst of a fast sync?)
• The contract has been self destructed
• The contract threw an error during deployment.

[pipermerriam]

Closed as it is very unlikely this is a web3.py bug. Please continue to post here if you still have issues and we can re-open if it turns out to be a web3.py issue.

[gutfeeling]

The node is definitely not fully synced. I was stumped because all transaction related queries returned fine, however getCode didn't return the correct values. When the node syncs fully, will report back if the problem is resolved.

[pipermerriam]

👍 your description fits. Fast sync finishes syncing Blocks/Transactions/Receipts well before the state sync finished and the contract code is part of the state sync.