[tests] Fix flake8 warnings in feature_block.py

1 files changed, 109 insertions, 100 deletions

diff --git a/test/functional/feature_block.py b/test/functional/feature_block.py
index fe9bbda14b..59c336e11d 100755
--- a/test/functional/feature_block.py
+++ b/test/functional/feature_block.py
@@ -2,15 +2,48 @@
 # Copyright (c) 2015-2017 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
-"""Test block processing.
-
-This reimplements tests from the bitcoinj/FullBlockTestGenerator used
-by the pull-tester.
-
-We use the testing framework in which we expect a particular answer from
-each test.
-"""
+"""Test block processing."""
+import copy
+import struct
+import time
 
+from test_framework.blocktools import create_block, create_coinbase, create_transaction, get_legacy_sigopcount_block
+from test_framework.comptool import RejectResult, TestInstance, TestManager
+from test_framework.key import CECKey
+from test_framework.messages import (
+    CBlock,
+    CBlockHeader,
+    COIN,
+    COutPoint,
+    CTransaction,
+    CTxIn,
+    CTxOut,
+    MAX_BLOCK_BASE_SIZE,
+    uint256_from_compact,
+    uint256_from_str,
+)
+from test_framework.mininode import network_thread_start
+from test_framework.script import (
+    CScript,
+    MAX_SCRIPT_ELEMENT_SIZE,
+    OP_2DUP,
+    OP_CHECKMULTISIG,
+    OP_CHECKMULTISIGVERIFY,
+    OP_CHECKSIG,
+    OP_CHECKSIGVERIFY,
+    OP_ELSE,
+    OP_ENDIF,
+    OP_EQUAL,
+    OP_FALSE,
+    OP_HASH160,
+    OP_IF,
+    OP_INVALIDOPCODE,
+    OP_RETURN,
+    OP_TRUE,
+    SIGHASH_ALL,
+    SignatureHash,
+    hash160,
+)
 from test_framework.test_framework import ComparisonTestFramework
 from test_framework.util import *
 from test_framework.comptool import TestManager, TestInstance, RejectResult
@@ -18,11 +51,10 @@ from test_framework.blocktools import *
 import time
 from test_framework.key import CECKey
 from test_framework.script import *
-from test_framework.mininode import network_thread_start
 import struct
 
 class PreviousSpendableOutput():
-    def __init__(self, tx = CTransaction(), n = -1):
+    def __init__(self, tx=CTransaction(), n=-1):
         self.tx = tx
         self.n = n  # the output we're spending
 
@@ -76,7 +108,7 @@ class FullBlockTest(ComparisonTestFramework):
         self.test.run()
 
     def add_transactions_to_block(self, block, tx_list):
-        [ tx.rehash() for tx in tx_list ]
+        [tx.rehash() for tx in tx_list]
         block.vtx.extend(tx_list)
 
     # this is a little handier to use than the version in blocktools.py
@@ -101,9 +133,9 @@ class FullBlockTest(ComparisonTestFramework):
         return tx
 
     def next_block(self, number, spend=None, additional_coinbase_value=0, script=CScript([OP_TRUE]), solve=True):
-        if self.tip == None:
+        if self.tip is None:
             base_block_hash = self.genesis_hash
-            block_time = int(time.time())+1
+            block_time = int(time.time()) + 1
         else:
             base_block_hash = self.tip.sha256
             block_time = self.tip.nTime + 1
@@ -112,10 +144,10 @@ class FullBlockTest(ComparisonTestFramework):
         coinbase = create_coinbase(height, self.coinbase_pubkey)
         coinbase.vout[0].nValue += additional_coinbase_value
         coinbase.rehash()
-        if spend == None:
+        if spend is None:
             block = create_block(base_block_hash, coinbase, block_time)
         else:
-            coinbase.vout[0].nValue += spend.tx.vout[spend.n].nValue - 1 # all but one satoshi to fees
+            coinbase.vout[0].nValue += spend.tx.vout[spend.n].nValue - 1  # all but one satoshi to fees
             coinbase.rehash()
             block = create_block(base_block_hash, coinbase, block_time)
             tx = create_transaction(spend.tx, spend.n, b"", 1, script)  # spend 1 satoshi
@@ -148,7 +180,7 @@ class FullBlockTest(ComparisonTestFramework):
             return TestInstance([[self.tip, True]])
 
         # returns a test case that asserts that the current tip was rejected
-        def rejected(reject = None):
+        def rejected(reject=None):
             if reject is None:
                 return TestInstance([[self.tip, False]])
             else:
@@ -181,14 +213,12 @@ class FullBlockTest(ComparisonTestFramework):
         # these must be updated if consensus changes
         MAX_BLOCK_SIGOPS = 20000
 
-
         # Create a new block
         block(0)
         save_spendable_output()
         yield accepted()
 
-
-        # Now we need that block to mature so we can spend the coinbase.
+        #  Now we need that block to mature so we can spend the coinbase.
         test = TestInstance(sync_every_block=False)
         for i in range(99):
             block(5000 + i)
@@ -223,7 +253,6 @@ class FullBlockTest(ComparisonTestFramework):
         txout_b3 = PreviousSpendableOutput(b3.vtx[1], 0)
         yield rejected()
 
-
         # Now we add another block to make the alternative chain longer.
         #
         #     genesis -> b1 (0) -> b2 (1)
@@ -231,7 +260,6 @@ class FullBlockTest(ComparisonTestFramework):
         block(4, spend=out[2])
         yield accepted()
 
-
         # ... and back to the first chain.
         #     genesis -> b1 (0) -> b2 (1) -> b5 (2) -> b6 (3)
         #                      \-> b3 (1) -> b4 (2)
@@ -273,7 +301,6 @@ class FullBlockTest(ComparisonTestFramework):
         block(11, spend=out[4], additional_coinbase_value=1)
         yield rejected(RejectResult(16, b'bad-cb-amount'))
 
-
         # Try again, but with a valid fork first
         #     genesis -> b1 (0) -> b2 (1) -> b5 (2) -> b6  (3)
         #                                          \-> b12 (3) -> b13 (4) -> b14 (5)
@@ -293,7 +320,7 @@ class FullBlockTest(ComparisonTestFramework):
         block(14, spend=out[5], additional_coinbase_value=1)
         yield rejected()
 
-        yield TestInstance([[b12, True, b13.sha256]]) # New tip should be b13.
+        yield TestInstance([[b12, True, b13.sha256]])  # New tip should be b13.
 
         # Add a block with MAX_BLOCK_SIGOPS and one with one more sigop
         #     genesis -> b1 (0) -> b2 (1) -> b5 (2) -> b6  (3)
@@ -307,13 +334,11 @@ class FullBlockTest(ComparisonTestFramework):
         yield accepted()
         save_spendable_output()
 
-
         # Test that a block with too many checksigs is rejected
         too_many_checksigs = CScript([OP_CHECKSIG] * (MAX_BLOCK_SIGOPS))
         block(16, spend=out[6], script=too_many_checksigs)
         yield rejected(RejectResult(16, b'bad-blk-sigops'))
 
-
         # Attempt to spend a transaction created on a different fork
         #     genesis -> b1 (0) -> b2 (1) -> b5 (2) -> b6  (3)
         #                                          \-> b12 (3) -> b13 (4) -> b15 (5) -> b17 (b3.vtx[1])
@@ -376,10 +401,10 @@ class FullBlockTest(ComparisonTestFramework):
         tip(15)
         b24 = block(24, spend=out[6])
         script_length = MAX_BLOCK_BASE_SIZE - len(b24.serialize()) - 69
-        script_output = CScript([b'\x00' * (script_length+1)])
+        script_output = CScript([b'\x00' * (script_length + 1)])
         tx.vout = [CTxOut(0, script_output)]
         b24 = update_block(24, [tx])
-        assert_equal(len(b24.serialize()), MAX_BLOCK_BASE_SIZE+1)
+        assert_equal(len(b24.serialize()), MAX_BLOCK_BASE_SIZE + 1)
         yield rejected(RejectResult(16, b'bad-blk-length'))
 
         block(25, spend=out[7])
@@ -433,7 +458,7 @@ class FullBlockTest(ComparisonTestFramework):
         #
 
         # MULTISIG: each op code counts as 20 sigops.  To create the edge case, pack another 19 sigops at the end.
-        lots_of_multisigs = CScript([OP_CHECKMULTISIG] * ((MAX_BLOCK_SIGOPS-1) // 20) + [OP_CHECKSIG] * 19)
+        lots_of_multisigs = CScript([OP_CHECKMULTISIG] * ((MAX_BLOCK_SIGOPS - 1) // 20) + [OP_CHECKSIG] * 19)
         b31 = block(31, spend=out[8], script=lots_of_multisigs)
         assert_equal(get_legacy_sigopcount_block(b31), MAX_BLOCK_SIGOPS)
         yield accepted()
@@ -445,10 +470,9 @@ class FullBlockTest(ComparisonTestFramework):
         assert_equal(get_legacy_sigopcount_block(b32), MAX_BLOCK_SIGOPS + 1)
         yield rejected(RejectResult(16, b'bad-blk-sigops'))
 
-
         # CHECKMULTISIGVERIFY
         tip(31)
-        lots_of_multisigs = CScript([OP_CHECKMULTISIGVERIFY] * ((MAX_BLOCK_SIGOPS-1) // 20) + [OP_CHECKSIG] * 19)
+        lots_of_multisigs = CScript([OP_CHECKMULTISIGVERIFY] * ((MAX_BLOCK_SIGOPS - 1) // 20) + [OP_CHECKSIG] * 19)
         block(33, spend=out[9], script=lots_of_multisigs)
         yield accepted()
         save_spendable_output()
@@ -457,7 +481,6 @@ class FullBlockTest(ComparisonTestFramework):
         block(34, spend=out[10], script=too_many_multisigs)
         yield rejected(RejectResult(16, b'bad-blk-sigops'))
 
-
         # CHECKSIGVERIFY
         tip(33)
         lots_of_checksigs = CScript([OP_CHECKSIGVERIFY] * (MAX_BLOCK_SIGOPS - 1))
@@ -469,7 +492,6 @@ class FullBlockTest(ComparisonTestFramework):
         block(36, spend=out[11], script=too_many_checksigs)
         yield rejected(RejectResult(16, b'bad-blk-sigops'))
 
-
         # Check spending of a transaction in a block which failed to connect
         #
         # b6  (3)
@@ -508,7 +530,7 @@ class FullBlockTest(ComparisonTestFramework):
         b39_sigops_per_output = 6
 
         # Build the redeem script, hash it, use hash to create the p2sh script
-        redeem_script = CScript([self.coinbase_pubkey] + [OP_2DUP, OP_CHECKSIGVERIFY]*5 + [OP_CHECKSIG])
+        redeem_script = CScript([self.coinbase_pubkey] + [OP_2DUP, OP_CHECKSIGVERIFY] * 5 + [OP_CHECKSIG])
         redeem_script_hash = hash160(redeem_script)
         p2sh_script = CScript([OP_HASH160, redeem_script_hash, OP_EQUAL])
 
@@ -525,7 +547,7 @@ class FullBlockTest(ComparisonTestFramework):
         # Until block is full, add tx's with 1 satoshi to p2sh_script, the rest to OP_TRUE
         tx_new = None
         tx_last = tx
-        total_size=len(b39.serialize())
+        total_size = len(b39.serialize())
         while(total_size < MAX_BLOCK_BASE_SIZE):
             tx_new = create_tx(tx_last, 1, 1, p2sh_script)
             tx_new.vout.append(CTxOut(tx_last.vout[1].nValue - 1, CScript([OP_TRUE])))
@@ -533,7 +555,7 @@ class FullBlockTest(ComparisonTestFramework):
             total_size += len(tx_new.serialize())
             if total_size >= MAX_BLOCK_BASE_SIZE:
                 break
-            b39.vtx.append(tx_new) # add tx to block
+            b39.vtx.append(tx_new)  # add tx to block
             tx_last = tx_new
             b39_outputs += 1
 
@@ -541,7 +563,6 @@ class FullBlockTest(ComparisonTestFramework):
         yield accepted()
         save_spendable_output()
 
-
         # Test sigops in P2SH redeem scripts
         #
         # b40 creates 3333 tx's spending the 6-sigop P2SH outputs from b39 for a total of 19998 sigops.
@@ -557,7 +578,7 @@ class FullBlockTest(ComparisonTestFramework):
 
         lastOutpoint = COutPoint(b40.vtx[1].sha256, 0)
         new_txs = []
-        for i in range(1, numTxes+1):
+        for i in range(1, numTxes + 1):
             tx = CTransaction()
             tx.vout.append(CTxOut(1, CScript([OP_TRUE])))
             tx.vin.append(CTxIn(lastOutpoint, b''))
@@ -608,7 +629,6 @@ class FullBlockTest(ComparisonTestFramework):
         yield accepted()
         save_spendable_output()
 
-
         # Test a number of really invalid scenarios
         #
         #  -> b31 (8) -> b33 (9) -> b35 (10) -> b39 (11) -> b42 (12) -> b43 (13) -> b44 (14)
@@ -640,7 +660,7 @@ class FullBlockTest(ComparisonTestFramework):
         b45.hashMerkleRoot = b45.calc_merkle_root()
         b45.calc_sha256()
         b45.solve()
-        self.block_heights[b45.sha256] = self.block_heights[self.tip.sha256]+1
+        self.block_heights[b45.sha256] = self.block_heights[self.tip.sha256] + 1
         self.tip = b45
         self.blocks[45] = b45
         yield rejected(RejectResult(16, b'bad-cb-missing'))
@@ -648,24 +668,23 @@ class FullBlockTest(ComparisonTestFramework):
         # A block with no txns
         tip(44)
         b46 = CBlock()
-        b46.nTime = b44.nTime+1
+        b46.nTime = b44.nTime + 1
         b46.hashPrevBlock = b44.sha256
         b46.nBits = 0x207fffff
         b46.vtx = []
         b46.hashMerkleRoot = 0
         b46.solve()
-        self.block_heights[b46.sha256] = self.block_heights[b44.sha256]+1
+        self.block_heights[b46.sha256] = self.block_heights[b44.sha256] + 1
         self.tip = b46
         assert 46 not in self.blocks
         self.blocks[46] = b46
-        s = ser_uint256(b46.hashMerkleRoot)
         yield rejected(RejectResult(16, b'bad-blk-length'))
 
         # A block with invalid work
         tip(44)
         b47 = block(47, solve=False)
         target = uint256_from_compact(b47.nBits)
-        while b47.sha256 < target: #changed > to <
+        while b47.sha256 < target:  # changed > to <
             b47.nNonce += 1
             b47.rehash()
         yield rejected(RejectResult(16, b'high-hash'))
@@ -693,9 +712,9 @@ class FullBlockTest(ComparisonTestFramework):
 
         # A block with two coinbase txns
         tip(44)
-        b51 = block(51)
+        block(51)
         cb2 = create_coinbase(51, self.coinbase_pubkey)
-        b51 = update_block(51, [cb2])
+        update_block(51, [cb2])
         yield rejected(RejectResult(16, b'bad-cb-multiple'))
 
         # A block w/ duplicate txns
@@ -712,7 +731,7 @@ class FullBlockTest(ComparisonTestFramework):
         #
         tip(43)
         block(53, spend=out[14])
-        yield rejected() # rejected since b44 is at same height
+        yield rejected()  # rejected since b44 is at same height
         save_spendable_output()
 
         # invalid timestamp (b35 is 5 blocks back, so its time is MedianTimePast)
@@ -729,7 +748,6 @@ class FullBlockTest(ComparisonTestFramework):
         yield accepted()
         save_spendable_output()
 
-
         # Test CVE-2012-2459
         #
         # -> b42 (12) -> b43 (13) -> b53 (14) -> b55 (15) -> b57p2 (16)
@@ -737,7 +755,7 @@ class FullBlockTest(ComparisonTestFramework):
         #                                                \-> b56p2 (16)
         #                                                \-> b56   (16)
         #
-        # Merkle tree malleability (CVE-2012-2459): repeating sequences of transactions in a block without 
+        # Merkle tree malleability (CVE-2012-2459): repeating sequences of transactions in a block without
         #                           affecting the merkle root of a block, while still invalidating it.
         #                           See:  src/consensus/merkle.h
         #
@@ -768,7 +786,7 @@ class FullBlockTest(ComparisonTestFramework):
         tip(55)
         b56 = copy.deepcopy(b57)
         self.blocks[56] = b56
-        assert_equal(len(b56.vtx),3)
+        assert_equal(len(b56.vtx), 3)
         b56 = update_block(56, [tx1])
         assert_equal(b56.hash, b57.hash)
         yield rejected(RejectResult(16, b'bad-txns-duplicate'))
@@ -788,7 +806,7 @@ class FullBlockTest(ComparisonTestFramework):
         b56p2 = copy.deepcopy(b57p2)
         self.blocks["b56p2"] = b56p2
         assert_equal(b56p2.hash, b57p2.hash)
-        assert_equal(len(b56p2.vtx),6)
+        assert_equal(len(b56p2.vtx), 6)
         b56p2 = update_block("b56p2", [tx3, tx4])
         yield rejected(RejectResult(16, b'bad-txns-duplicate'))
 
@@ -796,7 +814,7 @@ class FullBlockTest(ComparisonTestFramework):
         yield accepted()
 
         tip(57)
-        yield rejected()  #rejected because 57p2 seen first
+        yield rejected()  # rejected because 57p2 seen first
         save_spendable_output()
 
         # Test a few invalid tx types
@@ -807,20 +825,20 @@ class FullBlockTest(ComparisonTestFramework):
 
         # tx with prevout.n out of range
         tip(57)
-        b58 = block(58, spend=out[17])
+        block(58, spend=out[17])
         tx = CTransaction()
         assert(len(out[17].tx.vout) < 42)
         tx.vin.append(CTxIn(COutPoint(out[17].tx.sha256, 42), CScript([OP_TRUE]), 0xffffffff))
         tx.vout.append(CTxOut(0, b""))
         tx.calc_sha256()
-        b58 = update_block(58, [tx])
+        update_block(58, [tx])
         yield rejected(RejectResult(16, b'bad-txns-inputs-missingorspent'))
 
         # tx with output value > input value out of range
         tip(57)
-        b59 = block(59)
-        tx = create_and_sign_tx(out[17].tx, out[17].n, 51*COIN)
-        b59 = update_block(59, [tx])
+        block(59)
+        tx = create_and_sign_tx(out[17].tx, out[17].n, 51 * COIN)
+        update_block(59, [tx])
         yield rejected(RejectResult(16, b'bad-txns-in-belowout'))
 
         # reset to good chain
@@ -840,31 +858,29 @@ class FullBlockTest(ComparisonTestFramework):
         #
         tip(60)
         b61 = block(61, spend=out[18])
-        b61.vtx[0].vin[0].scriptSig = b60.vtx[0].vin[0].scriptSig  #equalize the coinbases
+        b61.vtx[0].vin[0].scriptSig = b60.vtx[0].vin[0].scriptSig  # equalize the coinbases
         b61.vtx[0].rehash()
         b61 = update_block(61, [])
         assert_equal(b60.vtx[0].serialize(), b61.vtx[0].serialize())
         yield rejected(RejectResult(16, b'bad-txns-BIP30'))
 
-
         # Test tx.isFinal is properly rejected (not an exhaustive tx.isFinal test, that should be in data-driven transaction tests)
         #
         #   -> b39 (11) -> b42 (12) -> b43 (13) -> b53 (14) -> b55 (15) -> b57 (16) -> b60 (17)
         #                                                                                     \-> b62 (18)
         #
         tip(60)
-        b62 = block(62)
+        block(62)
         tx = CTransaction()
-        tx.nLockTime = 0xffffffff  #this locktime is non-final
+        tx.nLockTime = 0xffffffff  # this locktime is non-final
         assert(out[18].n < len(out[18].tx.vout))
-        tx.vin.append(CTxIn(COutPoint(out[18].tx.sha256, out[18].n))) # don't set nSequence
+        tx.vin.append(CTxIn(COutPoint(out[18].tx.sha256, out[18].n)))  # don't set nSequence
         tx.vout.append(CTxOut(0, CScript([OP_TRUE])))
         assert(tx.vin[0].nSequence < 0xffffffff)
         tx.calc_sha256()
-        b62 = update_block(62, [tx])
+        update_block(62, [tx])
         yield rejected(RejectResult(16, b'bad-txns-nonfinal'))
 
-
         # Test a non-final coinbase is also rejected
         #
         #   -> b39 (11) -> b42 (12) -> b43 (13) -> b53 (14) -> b55 (15) -> b57 (16) -> b60 (17)
@@ -878,7 +894,6 @@ class FullBlockTest(ComparisonTestFramework):
         b63 = update_block(63, [])
         yield rejected(RejectResult(16, b'bad-txns-nonfinal'))
 
-
         #  This checks that a block with a bloated VARINT between the block_header and the array of tx such that
         #  the block is > MAX_BLOCK_BASE_SIZE with the bloated varint, but <= MAX_BLOCK_BASE_SIZE without the bloated varint,
         #  does not cause a subsequent, identical block with canonical encoding to be rejected.  The test does not
@@ -976,13 +991,13 @@ class FullBlockTest(ComparisonTestFramework):
         #
         tip(65)
         block(68, additional_coinbase_value=10)
-        tx = create_and_sign_tx(out[20].tx, out[20].n, out[20].tx.vout[0].nValue-9)
+        tx = create_and_sign_tx(out[20].tx, out[20].n, out[20].tx.vout[0].nValue - 9)
         update_block(68, [tx])
         yield rejected(RejectResult(16, b'bad-cb-amount'))
 
         tip(65)
         b69 = block(69, additional_coinbase_value=10)
-        tx = create_and_sign_tx(out[20].tx, out[20].n, out[20].tx.vout[0].nValue-10)
+        tx = create_and_sign_tx(out[20].tx, out[20].n, out[20].tx.vout[0].nValue - 10)
         update_block(69, [tx])
         yield accepted()
         save_spendable_output()
@@ -1002,7 +1017,6 @@ class FullBlockTest(ComparisonTestFramework):
         update_block(70, [tx])
         yield rejected(RejectResult(16, b'bad-txns-inputs-missingorspent'))
 
-
         # Test accepting an invalid block which has the same hash as a valid one (via merkle tree tricks)
         #
         #  -> b53 (14) -> b55 (15) -> b57 (16) -> b60 (17) -> b64 (18) -> b65 (19) -> b69 (20) -> b72 (21)
@@ -1031,7 +1045,6 @@ class FullBlockTest(ComparisonTestFramework):
         yield accepted()
         save_spendable_output()
 
-
         # Test some invalid scripts and MAX_BLOCK_SIGOPS
         #
         # -> b55 (15) -> b57 (16) -> b60 (17) -> b64 (18) -> b65 (19) -> b69 (20) -> b72 (21)
@@ -1053,17 +1066,17 @@ class FullBlockTest(ComparisonTestFramework):
         b73 = block(73)
         size = MAX_BLOCK_SIGOPS - 1 + MAX_SCRIPT_ELEMENT_SIZE + 1 + 5 + 1
         a = bytearray([OP_CHECKSIG] * size)
-        a[MAX_BLOCK_SIGOPS - 1] = int("4e",16) # OP_PUSHDATA4
+        a[MAX_BLOCK_SIGOPS - 1] = int("4e", 16)  # OP_PUSHDATA4
 
         element_size = MAX_SCRIPT_ELEMENT_SIZE + 1
         a[MAX_BLOCK_SIGOPS] = element_size % 256
-        a[MAX_BLOCK_SIGOPS+1] = element_size // 256
-        a[MAX_BLOCK_SIGOPS+2] = 0
-        a[MAX_BLOCK_SIGOPS+3] = 0
+        a[MAX_BLOCK_SIGOPS + 1] = element_size // 256
+        a[MAX_BLOCK_SIGOPS + 2] = 0
+        a[MAX_BLOCK_SIGOPS + 3] = 0
 
         tx = create_and_sign_tx(out[22].tx, 0, 1, CScript(a))
         b73 = update_block(73, [tx])
-        assert_equal(get_legacy_sigopcount_block(b73), MAX_BLOCK_SIGOPS+1)
+        assert_equal(get_legacy_sigopcount_block(b73), MAX_BLOCK_SIGOPS + 1)
         yield rejected(RejectResult(16, b'bad-blk-sigops'))
 
         # b74/75 - if we push an invalid script element, all prevous sigops are counted,
@@ -1079,40 +1092,40 @@ class FullBlockTest(ComparisonTestFramework):
         #
         #
         tip(72)
-        b74 = block(74)
-        size = MAX_BLOCK_SIGOPS - 1 + MAX_SCRIPT_ELEMENT_SIZE + 42 # total = 20,561
+        block(74)
+        size = MAX_BLOCK_SIGOPS - 1 + MAX_SCRIPT_ELEMENT_SIZE + 42  # total = 20,561
         a = bytearray([OP_CHECKSIG] * size)
         a[MAX_BLOCK_SIGOPS] = 0x4e
-        a[MAX_BLOCK_SIGOPS+1] = 0xfe
-        a[MAX_BLOCK_SIGOPS+2] = 0xff
-        a[MAX_BLOCK_SIGOPS+3] = 0xff
-        a[MAX_BLOCK_SIGOPS+4] = 0xff
+        a[MAX_BLOCK_SIGOPS + 1] = 0xfe
+        a[MAX_BLOCK_SIGOPS + 2] = 0xff
+        a[MAX_BLOCK_SIGOPS + 3] = 0xff
+        a[MAX_BLOCK_SIGOPS + 4] = 0xff
         tx = create_and_sign_tx(out[22].tx, 0, 1, CScript(a))
-        b74 = update_block(74, [tx])
+        update_block(74, [tx])
         yield rejected(RejectResult(16, b'bad-blk-sigops'))
 
         tip(72)
-        b75 = block(75)
+        block(75)
         size = MAX_BLOCK_SIGOPS - 1 + MAX_SCRIPT_ELEMENT_SIZE + 42
         a = bytearray([OP_CHECKSIG] * size)
-        a[MAX_BLOCK_SIGOPS-1] = 0x4e
+        a[MAX_BLOCK_SIGOPS - 1] = 0x4e
         a[MAX_BLOCK_SIGOPS] = 0xff
-        a[MAX_BLOCK_SIGOPS+1] = 0xff
-        a[MAX_BLOCK_SIGOPS+2] = 0xff
-        a[MAX_BLOCK_SIGOPS+3] = 0xff
+        a[MAX_BLOCK_SIGOPS + 1] = 0xff
+        a[MAX_BLOCK_SIGOPS + 2] = 0xff
+        a[MAX_BLOCK_SIGOPS + 3] = 0xff
         tx = create_and_sign_tx(out[22].tx, 0, 1, CScript(a))
-        b75 = update_block(75, [tx])
+        update_block(75, [tx])
         yield accepted()
         save_spendable_output()
 
         # Check that if we push an element filled with CHECKSIGs, they are not counted
         tip(75)
-        b76 = block(76)
+        block(76)
         size = MAX_BLOCK_SIGOPS - 1 + MAX_SCRIPT_ELEMENT_SIZE + 1 + 5
         a = bytearray([OP_CHECKSIG] * size)
-        a[MAX_BLOCK_SIGOPS-1] = 0x4e # PUSHDATA4, but leave the following bytes as just checksigs
+        a[MAX_BLOCK_SIGOPS - 1] = 0x4e  # PUSHDATA4, but leave the following bytes as just checksigs
         tx = create_and_sign_tx(out[23].tx, 0, 1, CScript(a))
-        b76 = update_block(76, [tx])
+        update_block(76, [tx])
         yield accepted()
         save_spendable_output()
 
@@ -1136,18 +1149,18 @@ class FullBlockTest(ComparisonTestFramework):
         #
         tip(76)
         block(77)
-        tx77 = create_and_sign_tx(out[24].tx, out[24].n, 10*COIN)
+        tx77 = create_and_sign_tx(out[24].tx, out[24].n, 10 * COIN)
         update_block(77, [tx77])
         yield accepted()
         save_spendable_output()
 
         block(78)
-        tx78 = create_tx(tx77, 0, 9*COIN)
+        tx78 = create_tx(tx77, 0, 9 * COIN)
         update_block(78, [tx78])
         yield accepted()
 
         block(79)
-        tx79 = create_tx(tx78, 0, 8*COIN)
+        tx79 = create_tx(tx78, 0, 8 * COIN)
         update_block(79, [tx79])
         yield accepted()
 
@@ -1160,7 +1173,7 @@ class FullBlockTest(ComparisonTestFramework):
         save_spendable_output()
 
         block(81, spend=out[26])
-        yield rejected() # other chain is same length
+        yield rejected()  # other chain is same length
         save_spendable_output()
 
         block(82, spend=out[27])
@@ -1173,7 +1186,6 @@ class FullBlockTest(ComparisonTestFramework):
         assert(tx78.hash in mempool)
         assert(tx79.hash in mempool)
 
-
         # Test invalid opcodes in dead execution paths.
         #
         #  -> b81 (26) -> b82 (27) -> b83 (28)
@@ -1191,7 +1203,6 @@ class FullBlockTest(ComparisonTestFramework):
         yield accepted()
         save_spendable_output()
 
-
         # Reorg on/off blocks that have OP_RETURN in them (and try to spend them)
         #
         #  -> b81 (26) -> b82 (27) -> b83 (28) -> b84 (29) -> b87 (30) -> b88 (31)
@@ -1215,7 +1226,7 @@ class FullBlockTest(ComparisonTestFramework):
         tx4.vout.append(CTxOut(0, CScript([OP_RETURN])))
         tx5 = create_tx(tx1, 4, 0, CScript([OP_RETURN]))
 
-        update_block(84, [tx1,tx2,tx3,tx4,tx5])
+        update_block(84, [tx1, tx2, tx3, tx4, tx5])
         yield accepted()
         save_spendable_output()
 
@@ -1241,7 +1252,6 @@ class FullBlockTest(ComparisonTestFramework):
         update_block("89a", [tx])
         yield rejected()
 
-
         #  Test re-org of a week's worth of blocks (1088 blocks)
         #  This test takes a minute or two and can be accomplished in memory
         #
@@ -1249,7 +1259,7 @@ class FullBlockTest(ComparisonTestFramework):
             tip(88)
             LARGE_REORG_SIZE = 1088
             test1 = TestInstance(sync_every_block=False)
-            spend=out[32]
+            spend = out[32]
             for i in range(89, LARGE_REORG_SIZE + 89):
                 b = block(i, spend)
                 tx = CTransaction()
@@ -1270,7 +1280,7 @@ class FullBlockTest(ComparisonTestFramework):
             tip(88)
             test2 = TestInstance(sync_every_block=False)
             for i in range(89, LARGE_REORG_SIZE + 89):
-                block("alt"+str(i))
+                block("alt" + str(i))
                 test2.blocks_and_transactions.append([self.tip, False])
             yield test2
 
@@ -1288,6 +1298,5 @@ class FullBlockTest(ComparisonTestFramework):
             chain1_tip += 2
 
 
-
 if __name__ == '__main__':
     FullBlockTest().main()