Merge #12987: tests/tools: Enable additional Python flake8 rules for automatic linting via Travis

643aad17fa Enable additional flake8 rules (practicalswift)
f020aca297 Minor Python cleanups to make flake8 pass with the new rules enabled (practicalswift)

Pull request description:

  Enabled rules:

  ```
  * E242: tab after ','
  * E266: too many leading '#' for block comment
  * E401: multiple imports on one line
  * E402: module level import not at top of file
  * E701: multiple statements on one line (colon)
  * E901: SyntaxError: invalid syntax
  * E902: TokenError: EOF in multi-line string
  * F821: undefined name 'Foo'
  * W293: blank line contains whitespace
  * W606: 'async' and 'await' are reserved keywords starting with Python 3.7
  ```

  Note to reviewers:
  * In general we don't allow whitespace cleanups to existing code, but in order to allow for enabling Travis checking for these rules a few smaller whitespace cleanups had to made as part of this PR.
  * Use [this `?w=1` link](https://github.com/bitcoin/bitcoin/pull/12987/files?w=1) to show a diff without whitespace changes.

  Before this commit:

  ```
  $ flake8 -qq --statistics --ignore=B,C,E,F,I,N,W --select=E112,E113,E115,E116,E125,E131,E133,E223,E224,E242,E266,E271,E272,E273,E274,E275,E304,E306,E401,E402,E502,E701,E702,E703,E714,E721,E741,E742,E743,F401,E901,E902,F402,F404,F406,F407,F601,F602,F621,F622,F631,F701,F702,F703,F704,F705,F706,F707,F811,F812,F821,F822,F823,F831,F841,W292,W293,W504,W601,W602,W603,W604,W605,W606 .
  5     E266 too many leading '#' for block comment
  4     E401 multiple imports on one line
  6     E402 module level import not at top of file
  5     E701 multiple statements on one line (colon)
  1     F812 list comprehension redefines 'n' from line 159
  4     F821 undefined name 'ConnectionRefusedError'
  28    W293 blank line contains whitespace
  ```

  After this commit:

  ```
  $ flake8 -qq --statistics --ignore=B,C,E,F,I,N,W --select=E112,E113,E115,E116,E125,E131,E133,E223,E224,E242,E266,E271,E272,E273,E274,E275,E304,E306,E401,E402,E502,E701,E702,E703,E714,E721,E741,E742,E743,F401,E901,E902,F402,F404,F406,F407,F601,F602,F621,F622,F631,F701,F702,F703,F704,F705,F706,F707,F811,F812,F821,F822,F823,F831,F841,W292,W293,W504,W601,W602,W603,W604,W605,W606 .
  $
  ```

Tree-SHA512: fc7d5e752298a50d4248afc620ee2c173135b4ca008e48e02913ac968e5a24a5fd5396926047ec62f1d580d537434ccae01f249bb2f3338fa59dc630bf97ca7a

22 files changed, 69 insertions, 51 deletions

diff --git a/contrib/devtools/copyright_header.py b/contrib/devtools/copyright_header.py
index c817e794b..e7cccaab0 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 9c666673c..187ef75fb 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/lint-python.sh b/contrib/devtools/lint-python.sh
index 1469ce164..239337000 100755
--- a/contrib/devtools/lint-python.sh
+++ b/contrib/devtools/lint-python.sh
@@ -15,6 +15,8 @@
 # E133 closing bracket is missing indentation
 # E223 tab before operator
 # E224 tab after operator
+# E242 tab after ','
+# E266 too many leading '#' for block comment
 # E271 multiple spaces after keyword
 # E272 multiple spaces before keyword
 # E273 tab after keyword
@@ -22,7 +24,10 @@
 # E275 missing whitespace after keyword
 # E304 blank lines found after function decorator
 # E306 expected 1 blank line before a nested definition
+# E401 multiple imports on one line
+# E402 module level import not at top of file
 # E502 the backslash is redundant between brackets
+# E701 multiple statements on one line (colon)
 # E702 multiple statements on one line (semicolon)
 # E703 statement ends with a semicolon
 # E714 test for object identity should be "is not"
@@ -30,6 +35,8 @@
 # E741 do not use variables named "l", "O", or "I"
 # E742 do not define classes named "l", "O", or "I"
 # E743 do not define functions named "l", "O", or "I"
+# E901 SyntaxError: invalid syntax
+# E902 TokenError: EOF in multi-line string
 # F401 module imported but unused
 # F402 import module from line N shadowed by loop variable
 # F404 future import(s) name after other statements
@@ -49,16 +56,19 @@
 # F707 an except: block as not the last exception handler
 # F811 redefinition of unused name from line N
 # F812 list comprehension redefines 'foo' from line N
+# F821 undefined name 'Foo'
 # F822 undefined name name in __all__
 # F823 local variable name … referenced before assignment
 # F831 duplicate argument name in function definition
 # F841 local variable 'foo' is assigned to but never used
 # W292 no newline at end of file
+# W293 blank line contains whitespace
 # W504 line break after binary operator
 # W601 .has_key() is deprecated, use "in"
 # W602 deprecated form of raising exception
 # W603 "<>" is deprecated, use "!="
 # W604 backticks are deprecated, use "repr()"
 # W605 invalid escape sequence "x"
+# W606 'async' and 'await' are reserved keywords starting with Python 3.7
 
-flake8 --ignore=B,C,E,F,I,N,W --select=E112,E113,E115,E116,E125,E131,E133,E223,E224,E271,E272,E273,E274,E275,E304,E306,E502,E702,E703,E714,E721,E741,E742,E743,F401,F402,F404,F406,F407,F601,F602,F621,F622,F631,F701,F702,F703,F704,F705,F706,F707,F811,F812,F822,F823,F831,F841,W292,W504,W601,W602,W603,W604,W605 .
+flake8 --ignore=B,C,E,F,I,N,W --select=E112,E113,E115,E116,E125,E131,E133,E223,E224,E242,E266,E271,E272,E273,E274,E275,E304,E306,E401,E402,E502,E701,E702,E703,E714,E721,E741,E742,E743,F401,E901,E902,F402,F404,F406,F407,F601,F602,F621,F622,F631,F701,F702,F703,F704,F705,F706,F707,F811,F812,F821,F822,F823,F831,F841,W292,W293,W504,W601,W602,W603,W604,W605,W606 .
diff --git a/contrib/devtools/optimize-pngs.py b/contrib/devtools/optimize-pngs.py
index 565b19912..a75731ef7 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 4969e9682..c609e9b33 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 6b69c5b3a..e1304e26d 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 2790ef4ac..72eb7255f 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 6e253c994..59044e701 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 0dbb79a70..071bc722b 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 435160578..de15657d2 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 10cf51673..f9b978751 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 e5db9e18c..eee38ce64 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 ce6ec76c6..072ba6c7c 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 2eb1be47a..60859de7a 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 2ee33aa86..a48939d2e 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 485a8af3d..e54843b26 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 5546bf6b2..10c8475d0 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 4721809a3..581de0ed5 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 4d349db23..5f5bfcf68 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 9825e4d89..505014e48 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 d742ec461..7577c4a0d 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 f16756eea..8419d6b54 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"])