Add Zcash testnet (tZEC) network symbol for address generation

[Copilot]

Adds support for generating Zcash testnet addresses. Parameters extracted from src/chainparams.cpp in the Zcash repository.

Changes

• pycoin/symbols/tzec.py: New network symbol with testnet parameters:

  • Address prefix 0x1D25 (tm addresses)
  • Script prefix 0x1CBA (t2 addresses)
  • WIF prefix 0xEF
  • BIP32 prefixes 0x04358394/0x043587CF (tprv/tpub)

• tests/cmds/test_cases/ku/bip32_subpaths_tzec.txt: Test coverage using ku test format for address generation, WIF, and BIP32

Usage

from pycoin.symbols.tzec import network

key = network.keys.private(secret_exponent=12345)
print(key.address())  # tmBe4yt4qKAwAa5jCZ5nT2ECR5Yt372bNXP

bip32 = network.keys.bip32_seed(b"seed phrase")
print(bip32.hwif(as_private=1))  # tprv...

Follows the same pattern as other testnet implementations (e.g., tdash.py, xtn.py).

Original prompt

---

This section details on the original issue you should resolve

<issue_title>How to generate ZEC testnet addresses?</issue_title>
<issue_description>

pycoin/pycoin/symbols/zec.py

Line 4 in 256967d

symbol="ZEC", network_name="Zcash", subnet_name="mainnet",

</issue_description>

Comments on the Issue (you are @copilot in this section)

@richardkiss For coins that fork the bitcoin source code, this information can often be found in src/chainparams.cpp. Patches welcome! @richardkiss @copilot Want to give this a crack?

• Fixes How to generate ZEC testnet addresses? #329

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[richardkiss]

@copilot Can you add a ku test similar to the existing tests that use ku? Should require just text files, no code changes. We don't need the tzec_test.py file if you do it this way

[Copilot]

@copilot Can you add a ku test similar to the existing tests that use ku? Should require just text files, no code changes. We don't need the tzec_test.py file if you do it this way

Done! Replaced tests/tzec_test.py with tests/cmds/test_cases/ku/bip32_subpaths_tzec.txt that uses the ku test format like other networks. The test passes successfully. (commit ee4a6d8)

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• blockchain.info
  • Triggering command: /usr/bin/python3 python3 -m unittest tests.cmds.cmdline_test -v (dns block)
• blockexplorer.com
  • Triggering command: /usr/bin/python3 python3 -m unittest tests.cmds.cmdline_test -v (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)