diff --git a/test/functional/feature_assumevalid.py b/test/functional/feature_assumevalid.py
--- a/test/functional/feature_assumevalid.py
+++ b/test/functional/feature_assumevalid.py
@@ -33,20 +33,24 @@
 
 from test_framework.blocktools import (create_block, create_coinbase)
 from test_framework.key import CECKey
-from test_framework.mininode import (CBlockHeader,
-                                     COutPoint,
-                                     CTransaction,
-                                     CTxIn,
-                                     CTxOut,
-                                     network_thread_join,
-                                     network_thread_start,
-                                     P2PInterface,
-                                     msg_block,
-                                     msg_headers)
+from test_framework.messages import (
+    CBlockHeader,
+    COutPoint,
+    CTransaction,
+    CTxIn,
+    CTxOut,
+    msg_block,
+    msg_headers,
+)
+from test_framework.mininode import (
+    network_thread_join,
+    network_thread_start,
+    P2PInterface,
+)
 from test_framework.script import (CScript, OP_TRUE)
 from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import assert_equal
 from test_framework.txtools import pad_tx
+from test_framework.util import assert_equal
 
 
 class BaseNode(P2PInterface):
diff --git a/test/functional/feature_bip68_sequence.py b/test/functional/feature_bip68_sequence.py
--- a/test/functional/feature_bip68_sequence.py
+++ b/test/functional/feature_bip68_sequence.py
@@ -7,12 +7,33 @@
 # Test BIP68 implementation
 #
 
+import time
+
+from test_framework.blocktools import (
+    create_block,
+    create_coinbase,
+)
+from test_framework.messages import (
+    COIN,
+    COutPoint,
+    CTransaction,
+    CTxIn,
+    CTxOut,
+    FromHex,
+    ToHex,
+)
+from test_framework.script import CScript
 from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import *
-from test_framework.script import *
-from test_framework.mininode import *
-from test_framework.blocktools import *
 from test_framework.txtools import pad_tx
+from test_framework.util import (
+    assert_equal,
+    assert_greater_than,
+    assert_raises_rpc_error,
+    connect_nodes,
+    disconnect_nodes,
+    satoshi_round,
+    sync_blocks,
+)
 
 SEQUENCE_LOCKTIME_DISABLE_FLAG = (1 << 31)
 SEQUENCE_LOCKTIME_TYPE_FLAG = (1 << 22)  # this means use time (0 means height)
diff --git a/test/functional/feature_block.py b/test/functional/feature_block.py
--- a/test/functional/feature_block.py
+++ b/test/functional/feature_block.py
@@ -4,16 +4,58 @@
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-from test_framework.test_framework import ComparisonTestFramework
-from test_framework.util import *
-from test_framework.comptool import TestManager, TestInstance, RejectResult
-from test_framework.blocktools import *
+import copy
+import struct
 import time
+
+from test_framework.blocktools import (
+    create_block,
+    create_coinbase,
+    create_transaction,
+    get_legacy_sigopcount_block,
+    make_conform_to_ctor,
+)
+from test_framework.cdefs import LEGACY_MAX_BLOCK_SIZE, MAX_BLOCK_SIGOPS_PER_MB
+from test_framework.comptool import RejectResult, TestInstance, TestManager
 from test_framework.key import CECKey
-from test_framework.script import *
+from test_framework.messages import (
+    CBlock,
+    CBlockHeader,
+    COIN,
+    COutPoint,
+    CTransaction,
+    CTxIn,
+    CTxOut,
+    ser_uint256,
+    uint256_from_compact,
+    uint256_from_str,
+)
 from test_framework.mininode import network_thread_start
-import struct
-from test_framework.cdefs import LEGACY_MAX_BLOCK_SIZE, MAX_BLOCK_SIGOPS_PER_MB
+from test_framework.script import (
+    CScript,
+    hash160,
+    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,
+    SIGHASH_FORKID,
+    SignatureHashForkId,
+)
+from test_framework.test_framework import ComparisonTestFramework
+from test_framework.txtools import pad_tx
+from test_framework.util import assert_equal
 
 
 class PreviousSpendableOutput():
diff --git a/test/functional/feature_cltv.py b/test/functional/feature_cltv.py
--- a/test/functional/feature_cltv.py
+++ b/test/functional/feature_cltv.py
@@ -8,12 +8,30 @@
 1351.
 """
 
+from test_framework.blocktools import create_block, create_coinbase
+from test_framework.messages import (
+    CTransaction,
+    FromHex,
+    msg_block,
+    msg_tx,
+    ToHex,
+)
+from test_framework.mininode import (
+    mininode_lock,
+    network_thread_start,
+    P2PInterface,
+)
+from test_framework.script import (
+    CScript,
+    CScriptNum,
+    OP_1NEGATE,
+    OP_CHECKLOCKTIMEVERIFY,
+    OP_DROP,
+    OP_TRUE,
+)
 from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import *
-from test_framework.mininode import *
-from test_framework.blocktools import create_coinbase, create_block
-from test_framework.script import CScript, CScriptNum, OP_1NEGATE, OP_CHECKLOCKTIMEVERIFY, OP_DROP, OP_TRUE
 from test_framework.txtools import pad_tx
+from test_framework.util import assert_equal, wait_until
 
 CLTV_HEIGHT = 1351
 
diff --git a/test/functional/feature_config_args.py b/test/functional/feature_config_args.py
--- a/test/functional/feature_config_args.py
+++ b/test/functional/feature_config_args.py
@@ -3,8 +3,8 @@
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Test various command line arguments and configuration file parameters."""
-import time
 import os
+import time
 
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import get_datadir_path
diff --git a/test/functional/feature_csv_activation.py b/test/functional/feature_csv_activation.py
--- a/test/functional/feature_csv_activation.py
+++ b/test/functional/feature_csv_activation.py
@@ -40,14 +40,26 @@
 bip112tx_special - test negative argument to OP_CSV
 """
 
-from test_framework.test_framework import ComparisonTestFramework
-from test_framework.util import *
-from test_framework.mininode import ToHex, FromHex, CTransaction, network_thread_start, COIN
-from test_framework.blocktools import create_coinbase, create_block, make_conform_to_ctor
-from test_framework.comptool import TestInstance, TestManager
-from test_framework.script import *
+from decimal import Decimal
 import time
 
+from test_framework.blocktools import (
+    create_block,
+    create_coinbase,
+    make_conform_to_ctor,
+)
+from test_framework.comptool import TestInstance, TestManager
+from test_framework.messages import COIN, CTransaction, FromHex, ToHex
+from test_framework.mininode import network_thread_start
+from test_framework.script import (
+    CScript,
+    OP_CHECKSEQUENCEVERIFY,
+    OP_DROP,
+    OP_TRUE,
+)
+from test_framework.test_framework import ComparisonTestFramework
+from test_framework.util import assert_equal
+
 base_relative_locktime = 10
 seq_disable_flag = 1 << 31
 seq_random_high_bit = 1 << 25
diff --git a/test/functional/feature_dbcrash.py b/test/functional/feature_dbcrash.py
--- a/test/functional/feature_dbcrash.py
+++ b/test/functional/feature_dbcrash.py
@@ -31,11 +31,17 @@
 import sys
 import time
 
-from test_framework.mininode import *
-from test_framework.script import *
-from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import *
 from test_framework.blocktools import create_confirmed_utxos
+from test_framework.messages import (
+    COIN,
+    COutPoint,
+    CTransaction,
+    CTxIn,
+    CTxOut,
+    ToHex,
+)
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import assert_equal, hex_str_to_bytes
 
 HTTP_DISCONNECT_ERRORS = [http.client.CannotSendRequest]
 try:
diff --git a/test/functional/feature_dersig.py b/test/functional/feature_dersig.py
--- a/test/functional/feature_dersig.py
+++ b/test/functional/feature_dersig.py
@@ -7,11 +7,16 @@
 Test that the DERSIG soft-fork activates at (regtest) height 1251.
 """
 
-from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import *
-from test_framework.mininode import *
-from test_framework.blocktools import create_coinbase, create_block
+from test_framework.blocktools import create_block, create_coinbase
+from test_framework.messages import CTransaction, FromHex, msg_block
+from test_framework.mininode import (
+    mininode_lock,
+    network_thread_start,
+    P2PInterface,
+)
 from test_framework.script import CScript
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import assert_equal, wait_until
 
 DERSIG_HEIGHT = 1251
 
diff --git a/test/functional/feature_maxuploadtarget.py b/test/functional/feature_maxuploadtarget.py
--- a/test/functional/feature_maxuploadtarget.py
+++ b/test/functional/feature_maxuploadtarget.py
@@ -15,11 +15,12 @@
 from collections import defaultdict
 import time
 
-from test_framework.mininode import *
-from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import *
 from test_framework.cdefs import LEGACY_MAX_BLOCK_SIZE
 from test_framework.blocktools import mine_big_block
+from test_framework.messages import CInv, msg_getdata
+from test_framework.mininode import network_thread_start, P2PInterface
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import assert_equal
 
 
 class TestNode(P2PInterface):
diff --git a/test/functional/feature_minchainwork.py b/test/functional/feature_minchainwork.py
--- a/test/functional/feature_minchainwork.py
+++ b/test/functional/feature_minchainwork.py
@@ -18,7 +18,7 @@
 import time
 
 from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import connect_nodes, assert_equal
+from test_framework.util import assert_equal, connect_nodes
 
 # 2 hashes required per regtest block (with no difficulty adjustment)
 REGTEST_WORK_PER_BLOCK = 2
diff --git a/test/functional/feature_notifications.py b/test/functional/feature_notifications.py
--- a/test/functional/feature_notifications.py
+++ b/test/functional/feature_notifications.py
@@ -7,7 +7,7 @@
 import os
 
 from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import assert_equal, wait_until, connect_nodes_bi
+from test_framework.util import assert_equal, connect_nodes_bi, wait_until
 
 FORK_WARNING_MESSAGE = "Warning: Large-work fork detected, forking after block {}\n"
 
diff --git a/test/functional/feature_nulldummy.py b/test/functional/feature_nulldummy.py
--- a/test/functional/feature_nulldummy.py
+++ b/test/functional/feature_nulldummy.py
@@ -3,14 +3,15 @@
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import *
-from test_framework.messages import FromHex, ToHex
-from test_framework.mininode import CTransaction, network_thread_start
-from test_framework.blocktools import create_coinbase, create_block
-from test_framework.script import CScript
 import time
 
+from test_framework.blocktools import create_block, create_coinbase
+from test_framework.messages import CTransaction, FromHex, ToHex
+from test_framework.mininode import network_thread_start
+from test_framework.script import CScript
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import assert_equal, assert_raises_rpc_error
+
 NULLDUMMY_ERROR = "64: non-mandatory-script-verify-flag (Dummy CHECKMULTISIG argument must be zero)"
 
 
diff --git a/test/functional/feature_proxy.py b/test/functional/feature_proxy.py
--- a/test/functional/feature_proxy.py
+++ b/test/functional/feature_proxy.py
@@ -27,17 +27,22 @@
 addnode connect to generic DNS name
 '''
 
-import socket
 import os
+import socket
 
-from test_framework.socks5 import Socks5Configuration, Socks5Command, Socks5Server, AddressType
+from test_framework.netutil import test_ipv6_local
+from test_framework.socks5 import (
+    AddressType,
+    Socks5Command,
+    Socks5Configuration,
+    Socks5Server,
+)
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
+    assert_equal,
     PORT_MIN,
     PORT_RANGE,
-    assert_equal,
 )
-from test_framework.netutil import test_ipv6_local
 
 RANGE_BEGIN = PORT_MIN + 2 * PORT_RANGE  # Start after p2p and rpc ports
 
diff --git a/test/functional/feature_pruning.py b/test/functional/feature_pruning.py
--- a/test/functional/feature_pruning.py
+++ b/test/functional/feature_pruning.py
@@ -11,13 +11,20 @@
 # This test takes 30 mins or more (up to 2 hours)
 # ********
 
-from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import *
-from test_framework.blocktools import mine_big_block
-
 import time
 import os
 
+from test_framework.blocktools import mine_big_block
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import (
+    assert_equal,
+    assert_greater_than,
+    assert_raises_rpc_error,
+    connect_nodes,
+    sync_blocks,
+)
+
+
 MIN_BLOCKS_TO_KEEP = 288
 
 # Rescans start at the earliest block up to 2 hours before a key timestamp, so
diff --git a/test/functional/feature_reindex.py b/test/functional/feature_reindex.py
--- a/test/functional/feature_reindex.py
+++ b/test/functional/feature_reindex.py
@@ -6,9 +6,10 @@
 #
 # Test -reindex and -reindex-chainstate with CheckBlockIndex
 #
+import time
+
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import assert_equal
-import time
 
 
 class ReindexTest(BitcoinTestFramework):