Include block hash prefix in str(block)

Author: carver

docs/guides/understanding_the_mining_process.rst

@@ -385,4 +385,4 @@ zero value transfer transaction.
   ... )
 
   >>> chain.mine_block(mix_hash=mix_hash, nonce=nonce)
-  <ByzantiumBlock(#Block #1)>
+  <ByzantiumBlock(#Block #1-0x41f6..2913)>

eth/rlp/blocks.py

@@ -2,10 +2,13 @@
     Type
 )
 
+from eth_utils import (
+    humanize_hash,
+)
+
 from eth._utils.datatypes import (
     Configurable,
 )
-
 from eth.abc import (
     BlockAPI,
     SignedTransactionAPI,
@@ -29,4 +32,5 @@ def __repr__(self) -> str:
         return f'<{self.__class__.__name__}(#{str(self)})>'
 
     def __str__(self) -> str:
-        return f"Block #{self.number}"
+        clipped_hash = humanize_hash(self.hash)
+        return f"Block #{self.number}-0x{clipped_hash}"