[tests] fix flake8 warnings in script.py and bignum.py

test/functional/test_framework/bignum.py

@@ -4,19 +4,18 @@
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Big number routines.
 
+Functions for converting numbers to MPI format and Bitcoin-specific little
+endian format.
+
 This file is copied from python-bitcoinlib.
 """
-
 import struct
 
-
-# generic big endian MPI format
-
 def bn_bytes(v, have_ext=False):
     ext = 0
     if have_ext:
         ext = 1
-    return ((v.bit_length()+7)//8) + ext
+    return (v.bit_length() + 7) // 8 + ext
 
 def bn2bin(v):
     s = bytearray()

test/functional/test_framework/script.py

@@ -6,16 +6,21 @@
 
 This file is modified from python-bitcoinlib.
 """
-
-from .messages import CTransaction, CTxOut, sha256, hash256, uint256_from_str, ser_uint256, ser_string
-
 import hashlib
 import struct
 
 from .bignum import bn2vch
+from .messages import (
+    CTransaction,
+    CTxOut,
+    hash256,
+    ser_string,
+    ser_uint256,
+    sha256,
+    uint256_from_str,
+)
 
 MAX_SCRIPT_ELEMENT_SIZE = 520
-
 OPCODE_NAMES = {}
 
 def hash160(s):
@@ -506,7 +511,6 @@ class CScript(bytes):
                 else:
                     assert False  # shouldn't happen
 
-
                 data = bytes(self[i:i + datasize])
 
                 # Check for truncation