Minor Python cleanups to make flake8 pass with the new rules enabled

21 files changed, 58 insertions, 50 deletions

diff --git a/contrib/devtools/copyright_header.py b/contrib/devtools/copyright_header.py
index c817e794b9..e7cccaab03 100755
--- a/contrib/devtools/copyright_header.py
+++ b/contrib/devtools/copyright_header.py
@@ -286,7 +286,7 @@ Arguments:
 def report_cmd(argv):
     if len(argv) == 2:
         sys.exit(REPORT_USAGE)
-        
+
     base_directory = argv[2]
     if not os.path.exists(base_directory):
         sys.exit("*** bad <base_directory>: %s" % base_directory)
@@ -444,7 +444,7 @@ def print_file_action_message(filename, action):
 def update_cmd(argv):
     if len(argv) != 3:
         sys.exit(UPDATE_USAGE)
-    
+
     base_directory = argv[2]
     if not os.path.exists(base_directory):
         sys.exit("*** bad base_directory: %s" % base_directory)
@@ -570,13 +570,13 @@ def insert_cmd(argv):
     _, extension = os.path.splitext(filename)
     if extension not in ['.h', '.cpp', '.cc', '.c', '.py']:
         sys.exit("*** cannot insert for file extension %s" % extension)
-   
+
     if extension == '.py': 
         style = 'python'
     else:
         style = 'cpp'
     exec_insert_header(filename, style)
-         
+
 ################################################################################
 # UI
 ################################################################################
diff --git a/contrib/devtools/github-merge.py b/contrib/devtools/github-merge.py
index 9c666673cf..187ef75fb7 100755
--- a/contrib/devtools/github-merge.py
+++ b/contrib/devtools/github-merge.py
@@ -21,7 +21,8 @@ import argparse
 import hashlib
 import subprocess
 import sys
-import json,codecs
+import json
+import codecs
 try:
     from urllib.request import Request,urlopen
 except:
diff --git a/contrib/devtools/optimize-pngs.py b/contrib/devtools/optimize-pngs.py
index 565b199125..a75731ef76 100755
--- a/contrib/devtools/optimize-pngs.py
+++ b/contrib/devtools/optimize-pngs.py
@@ -41,19 +41,19 @@ for folder in folders:
             file_path = os.path.join(absFolder, file)
             fileMetaMap = {'file' : file, 'osize': os.path.getsize(file_path), 'sha256Old' : file_hash(file_path)}
             fileMetaMap['contentHashPre'] = content_hash(file_path)
-        
+
             try:
                 subprocess.call([pngcrush, "-brute", "-ow", "-rem", "gAMA", "-rem", "cHRM", "-rem", "iCCP", "-rem", "sRGB", "-rem", "alla", "-rem", "text", file_path],
                                 stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
             except:
                 print("pngcrush is not installed, aborting...")
                 sys.exit(0)
-        
+
             #verify
             if "Not a PNG file" in subprocess.check_output([pngcrush, "-n", "-v", file_path], stderr=subprocess.STDOUT, universal_newlines=True):
                 print("PNG file "+file+" is corrupted after crushing, check out pngcursh version")
                 sys.exit(1)
-            
+
             fileMetaMap['sha256New'] = file_hash(file_path)
             fileMetaMap['contentHashPost'] = content_hash(file_path)
 
@@ -72,5 +72,5 @@ for fileDict in outputArray:
     totalSaveBytes += fileDict['osize'] - fileDict['psize']
     noHashChange = noHashChange and (oldHash == newHash)
     print(fileDict['file']+"\n  size diff from: "+str(fileDict['osize'])+" to: "+str(fileDict['psize'])+"\n  old sha256: "+oldHash+"\n  new sha256: "+newHash+"\n")
-    
+
 print("completed. Checksum stable: "+str(noHashChange)+". Total reduction: "+str(totalSaveBytes)+" bytes")
diff --git a/contrib/linearize/linearize-data.py b/contrib/linearize/linearize-data.py
index 4969e96827..c609e9b336 100755
--- a/contrib/linearize/linearize-data.py
+++ b/contrib/linearize/linearize-data.py
@@ -21,7 +21,6 @@ from binascii import hexlify, unhexlify
 
 settings = {}
 
-##### Switch endian-ness #####
 def hex_switchEndian(s):
 	""" Switches the endianness of a hex string (in pairs of hex chars) """
 	pairList = [s[i:i+2].encode() for i in range(0, len(s), 2)]
diff --git a/contrib/linearize/linearize-hashes.py b/contrib/linearize/linearize-hashes.py
index 6b69c5b3a3..e1304e26d0 100755
--- a/contrib/linearize/linearize-hashes.py
+++ b/contrib/linearize/linearize-hashes.py
@@ -21,7 +21,6 @@ import os.path
 
 settings = {}
 
-##### Switch endian-ness #####
 def hex_switchEndian(s):
 	""" Switches the endianness of a hex string (in pairs of hex chars) """
 	pairList = [s[i:i+2].encode() for i in range(0, len(s), 2)]
diff --git a/contrib/seeds/generate-seeds.py b/contrib/seeds/generate-seeds.py
index 2790ef4acd..72eb7255f3 100755
--- a/contrib/seeds/generate-seeds.py
+++ b/contrib/seeds/generate-seeds.py
@@ -34,7 +34,8 @@ These should be pasted into `src/chainparamsseeds.h`.
 
 from base64 import b32decode
 from binascii import a2b_hex
-import sys, os
+import sys
+import os
 import re
 
 # ipv4 in ipv6 prefix
@@ -46,7 +47,7 @@ def name_to_ipv6(addr):
     if len(addr)>6 and addr.endswith('.onion'):
         vchAddr = b32decode(addr[0:-6], True)
         if len(vchAddr) != 16-len(pchOnionCat):
-            raise ValueError('Invalid onion %s' % s)
+            raise ValueError('Invalid onion %s' % vchAddr)
         return pchOnionCat + vchAddr
     elif '.' in addr: # IPv4
         return pchIPv4 + bytearray((int(x) for x in addr.split('.')))
@@ -132,7 +133,7 @@ def main():
     with open(os.path.join(indir,'nodes_test.txt'),'r') as f:
         process_nodes(g, f, 'pnSeed6_test', 18333)
     g.write('#endif // BITCOIN_CHAINPARAMSSEEDS_H\n')
-            
+
 if __name__ == '__main__':
     main()
 
diff --git a/contrib/seeds/makeseeds.py b/contrib/seeds/makeseeds.py
index 6e253c994d..59044e701a 100755
--- a/contrib/seeds/makeseeds.py
+++ b/contrib/seeds/makeseeds.py
@@ -6,6 +6,11 @@
 # Generate seeds.txt from Pieter's DNS seeder
 #
 
+import re
+import sys
+import dns.resolver
+import collections
+
 NSEEDS=512
 
 MAX_SEEDS_PER_ASN=2
@@ -22,11 +27,6 @@ SUSPICIOUS_HOSTS = {
     "54.94.195.96", "54.94.200.247"
 }
 
-import re
-import sys
-import dns.resolver
-import collections
-
 PATTERN_IPV4 = re.compile(r"^((\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})):(\d+)$")
 PATTERN_IPV6 = re.compile(r"^\[([0-9a-z:]+)\]:(\d+)$")
 PATTERN_ONION = re.compile(r"^([abcdefghijklmnopqrstuvwxyz234567]{16}\.onion):(\d+)$")
diff --git a/contrib/testgen/base58.py b/contrib/testgen/base58.py
index 0dbb79a707..071bc722b0 100644
--- a/contrib/testgen/base58.py
+++ b/contrib/testgen/base58.py
@@ -43,8 +43,10 @@ def b58encode(v):
     # leading 0-bytes in the input become leading-1s
     nPad = 0
     for c in v:
-        if c == 0: nPad += 1
-        else: break
+        if c == 0:
+            nPad += 1
+        else:
+            break
 
     return (__b58chars[0]*nPad) + result
 
@@ -98,7 +100,8 @@ def b58decode_chk(v):
 def get_bcaddress_version(strAddress):
     """ Returns None if strAddress is invalid.  Otherwise returns integer version of address. """
     addr = b58decode_chk(strAddress)
-    if addr is None or len(addr)!=21: return None
+    if addr is None or len(addr)!=21:
+        return None
     version = addr[0]
     return ord(version)
 
diff --git a/contrib/testgen/gen_base58_test_vectors.py b/contrib/testgen/gen_base58_test_vectors.py
index 4351605786..de15657d27 100755
--- a/contrib/testgen/gen_base58_test_vectors.py
+++ b/contrib/testgen/gen_base58_test_vectors.py
@@ -74,12 +74,12 @@ def gen_invalid_vector(template, corrupt_prefix, randomize_payload_size, corrupt
         prefix = os.urandom(1)
     else:
         prefix = bytearray(template[0])
-    
+
     if randomize_payload_size:
         payload = os.urandom(max(int(random.expovariate(0.5)), 50))
     else:
         payload = os.urandom(template[1])
-    
+
     if corrupt_suffix:
         suffix = os.urandom(len(template[2]))
     else:
@@ -114,7 +114,8 @@ def gen_invalid_vectors():
                 yield val,
 
 if __name__ == '__main__':
-    import sys, json
+    import sys
+    import json
     iters = {'valid':gen_valid_vectors, 'invalid':gen_invalid_vectors}
     try:
         uiter = iters[sys.argv[1]]
@@ -124,7 +125,7 @@ if __name__ == '__main__':
         count = int(sys.argv[2])
     except IndexError:
         count = 0
-   
+
     data = list(islice(uiter(), count))
     json.dump(data, sys.stdout, sort_keys=True, indent=4)
     sys.stdout.write('\n')
diff --git a/share/rpcauth/rpcauth.py b/share/rpcauth/rpcauth.py
index 10cf516732..f9b9787514 100755
--- a/share/rpcauth/rpcauth.py
+++ b/share/rpcauth/rpcauth.py
@@ -25,7 +25,7 @@ salt = "".join([x[2:] for x in hexseq])
 
 #Create 32 byte b64 password
 password = base64.urlsafe_b64encode(os.urandom(32)).decode("utf-8")
- 
+
 m = hmac.new(bytearray(salt, 'utf-8'), bytearray(password, 'utf-8'), "SHA256")
 result = m.hexdigest()
 
diff --git a/test/functional/feature_bip68_sequence.py b/test/functional/feature_bip68_sequence.py
index e5db9e18c7..eee38ce648 100755
--- a/test/functional/feature_bip68_sequence.py
+++ b/test/functional/feature_bip68_sequence.py
@@ -129,7 +129,7 @@ class BIP68Test(BitcoinTestFramework):
 
             # Track whether any sequence locks used should fail
             should_pass = True
-            
+
             # Track whether this transaction was built with sequence locks
             using_sequence_locks = False
 
@@ -343,7 +343,7 @@ class BIP68Test(BitcoinTestFramework):
         tx2.rehash()
 
         self.nodes[0].sendrawtransaction(ToHex(tx2))
-        
+
         # Now make an invalid spend of tx2 according to BIP68
         sequence_value = 100 # 100 block relative locktime
 
diff --git a/test/functional/feature_maxuploadtarget.py b/test/functional/feature_maxuploadtarget.py
index ce6ec76c61..072ba6c7c7 100755
--- a/test/functional/feature_maxuploadtarget.py
+++ b/test/functional/feature_maxuploadtarget.py
@@ -30,7 +30,7 @@ class TestP2PConn(P2PInterface):
         self.block_receive_map[message.block.sha256] += 1
 
 class MaxUploadTest(BitcoinTestFramework):
- 
+
     def set_test_params(self):
         self.setup_clean_chain = True
         self.num_nodes = 1
diff --git a/test/functional/feature_proxy.py b/test/functional/feature_proxy.py
index 2eb1be47a5..60859de7a5 100755
--- a/test/functional/feature_proxy.py
+++ b/test/functional/feature_proxy.py
@@ -182,7 +182,7 @@ class ProxyTest(BitcoinTestFramework):
         assert_equal(n1['onion']['proxy'], '%s:%i' % (self.conf2.addr))
         assert_equal(n1['onion']['proxy_randomize_credentials'], False)
         assert_equal(n1['onion']['reachable'], True)
-        
+
         n2 = networks_dict(self.nodes[2].getnetworkinfo())
         for net in ['ipv4','ipv6','onion']:
             assert_equal(n2[net]['proxy'], '%s:%i' % (self.conf2.addr))
diff --git a/test/functional/interface_rest.py b/test/functional/interface_rest.py
index 2ee33aa869..a48939d2e0 100755
--- a/test/functional/interface_rest.py
+++ b/test/functional/interface_rest.py
@@ -186,10 +186,10 @@ class RESTTest (BitcoinTestFramework):
         self.test_rest_request("/getutxos/checkmempool", http_method='POST', req_type=ReqType.JSON, status=400, ret_type=RetType.OBJ)
 
         # Test limits
-        long_uri = '/'.join(["{}-{}".format(txid, n) for n in range(20)])
+        long_uri = '/'.join(["{}-{}".format(txid, n_) for n_ in range(20)])
         self.test_rest_request("/getutxos/checkmempool/{}".format(long_uri), http_method='POST', status=400, ret_type=RetType.OBJ)
 
-        long_uri = '/'.join(['{}-{}'.format(txid, n) for n in range(15)])
+        long_uri = '/'.join(['{}-{}'.format(txid, n_) for n_ in range(15)])
         self.test_rest_request("/getutxos/checkmempool/{}".format(long_uri), http_method='POST', status=200)
 
         self.nodes[0].generate(1)  # generate block to not affect upcoming tests
diff --git a/test/functional/p2p_mempool.py b/test/functional/p2p_mempool.py
index 485a8af3d0..e54843b26f 100755
--- a/test/functional/p2p_mempool.py
+++ b/test/functional/p2p_mempool.py
@@ -30,6 +30,6 @@ class P2PMempoolTests(BitcoinTestFramework):
 
         #mininode must be disconnected at this point
         assert_equal(len(self.nodes[0].getpeerinfo()), 0)
-    
+
 if __name__ == '__main__':
     P2PMempoolTests().main()
diff --git a/test/functional/p2p_segwit.py b/test/functional/p2p_segwit.py
index 5546bf6b29..10c8475d01 100755
--- a/test/functional/p2p_segwit.py
+++ b/test/functional/p2p_segwit.py
@@ -450,7 +450,7 @@ class SegWitTest(BitcoinTestFramework):
         block = self.build_next_block()
 
         assert(len(self.utxo) > 0)
-        
+
         # Create a P2WSH transaction.
         # The witness program will be a bunch of OP_2DROP's, followed by OP_TRUE.
         # This should give us plenty of room to tweak the spending tx's
@@ -562,7 +562,7 @@ class SegWitTest(BitcoinTestFramework):
         self.log.info("Testing extra witness data in tx")
 
         assert(len(self.utxo) > 0)
-        
+
         block = self.build_next_block()
 
         witness_program = CScript([OP_DROP, OP_TRUE])
@@ -730,7 +730,7 @@ class SegWitTest(BitcoinTestFramework):
         witness_program = CScript([OP_DROP, OP_TRUE])
         witness_hash = sha256(witness_program)
         scriptPubKey = CScript([OP_0, witness_hash])
-        
+
         # Create a transaction that splits our utxo into many outputs
         tx = CTransaction()
         tx.vin.append(CTxIn(COutPoint(self.utxo[0].sha256, self.utxo[0].n), b""))
diff --git a/test/functional/test_framework/socks5.py b/test/functional/test_framework/socks5.py
index 4721809a3b..581de0ed5d 100644
--- a/test/functional/test_framework/socks5.py
+++ b/test/functional/test_framework/socks5.py
@@ -4,12 +4,14 @@
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Dummy Socks5 server for testing."""
 
-import socket, threading, queue
+import socket
+import threading
+import queue
 import logging
 
 logger = logging.getLogger("TestFramework.socks5")
 
-### Protocol constants
+# Protocol constants
 class Command:
     CONNECT = 0x01
 
@@ -18,7 +20,7 @@ class AddressType:
     DOMAINNAME = 0x03
     IPV6 = 0x04
 
-### Utility functions
+# Utility functions
 def recvall(s, n):
     """Receive n bytes from a socket, or fail."""
     rv = bytearray()
@@ -30,7 +32,7 @@ def recvall(s, n):
         n -= len(d)
     return rv
 
-### Implementation classes
+# Implementation classes
 class Socks5Configuration():
     """Proxy configuration."""
     def __init__(self):
@@ -141,7 +143,7 @@ class Socks5Server():
                 thread = threading.Thread(None, conn.handle)
                 thread.daemon = True
                 thread.start()
-    
+
     def start(self):
         assert(not self.running)
         self.running = True
diff --git a/test/functional/wallet_importprunedfunds.py b/test/functional/wallet_importprunedfunds.py
index 4d349db23f..5f5bfcf683 100755
--- a/test/functional/wallet_importprunedfunds.py
+++ b/test/functional/wallet_importprunedfunds.py
@@ -16,7 +16,7 @@ class ImportPrunedFundsTest(BitcoinTestFramework):
         self.nodes[0].generate(101)
 
         self.sync_all()
-        
+
         # address
         address1 = self.nodes[0].getnewaddress()
         # pubkey
diff --git a/test/functional/wallet_keypool.py b/test/functional/wallet_keypool.py
index 9825e4d894..505014e48f 100755
--- a/test/functional/wallet_keypool.py
+++ b/test/functional/wallet_keypool.py
@@ -17,7 +17,7 @@ class KeyPoolTest(BitcoinTestFramework):
         addr_before_encrypting_data = nodes[0].getaddressinfo(addr_before_encrypting)
         wallet_info_old = nodes[0].getwalletinfo()
         assert(addr_before_encrypting_data['hdmasterkeyid'] == wallet_info_old['hdmasterkeyid'])
-        
+
         # Encrypt wallet and wait to terminate
         nodes[0].node_encrypt_wallet('test')
         # Restart node 0
diff --git a/test/functional/wallet_txn_clone.py b/test/functional/wallet_txn_clone.py
index d742ec4618..7577c4a0d2 100755
--- a/test/functional/wallet_txn_clone.py
+++ b/test/functional/wallet_txn_clone.py
@@ -92,7 +92,8 @@ class TxnMallTest(BitcoinTestFramework):
         # Node0's balance should be starting balance, plus 50BTC for another
         # matured block, minus tx1 and tx2 amounts, and minus transaction fees:
         expected = starting_balance + fund_foo_tx["fee"] + fund_bar_tx["fee"]
-        if self.options.mine_block: expected += 50
+        if self.options.mine_block:
+            expected += 50
         expected += tx1["amount"] + tx1["fee"]
         expected += tx2["amount"] + tx2["fee"]
         assert_equal(self.nodes[0].getbalance(), expected)
@@ -131,7 +132,7 @@ class TxnMallTest(BitcoinTestFramework):
         tx1 = self.nodes[0].gettransaction(txid1)
         tx1_clone = self.nodes[0].gettransaction(txid1_clone)
         tx2 = self.nodes[0].gettransaction(txid2)
-        
+
         # Verify expected confirmations
         assert_equal(tx1["confirmations"], -2)
         assert_equal(tx1_clone["confirmations"], 2)
diff --git a/test/functional/wallet_txn_doublespend.py b/test/functional/wallet_txn_doublespend.py
index f16756eeaa..8419d6b545 100755
--- a/test/functional/wallet_txn_doublespend.py
+++ b/test/functional/wallet_txn_doublespend.py
@@ -27,7 +27,7 @@ class TxnMallTest(BitcoinTestFramework):
         for i in range(4):
             assert_equal(self.nodes[i].getbalance(), starting_balance)
             self.nodes[i].getnewaddress("")  # bug workaround, coins generated assigned to first getnewaddress!
-        
+
         # Assign coins to foo and bar accounts:
         node0_address_foo = self.nodes[0].getnewaddress("foo")
         fund_foo_txid = self.nodes[0].sendfrom("", node0_address_foo, 1219)
@@ -64,7 +64,7 @@ class TxnMallTest(BitcoinTestFramework):
         # Create two spends using 1 50 BTC coin each
         txid1 = self.nodes[0].sendfrom("foo", node1_address, 40, 0)
         txid2 = self.nodes[0].sendfrom("bar", node1_address, 20, 0)
-        
+
         # Have node0 mine a block:
         if (self.options.mine_block):
             self.nodes[0].generate(1)
@@ -76,7 +76,8 @@ class TxnMallTest(BitcoinTestFramework):
         # Node0's balance should be starting balance, plus 50BTC for another
         # matured block, minus 40, minus 20, and minus transaction fees:
         expected = starting_balance + fund_foo_tx["fee"] + fund_bar_tx["fee"]
-        if self.options.mine_block: expected += 50
+        if self.options.mine_block:
+            expected += 50
         expected += tx1["amount"] + tx1["fee"]
         expected += tx2["amount"] + tx2["fee"]
         assert_equal(self.nodes[0].getbalance(), expected)
@@ -93,7 +94,7 @@ class TxnMallTest(BitcoinTestFramework):
         else:
             assert_equal(tx1["confirmations"], 0)
             assert_equal(tx2["confirmations"], 0)
-        
+
         # Now give doublespend and its parents to miner:
         self.nodes[2].sendrawtransaction(fund_foo_tx["hex"])
         self.nodes[2].sendrawtransaction(fund_bar_tx["hex"])