From c7399e7082805de6d04e9bf2e8bacd49e3adaae5 Mon Sep 17 00:00:00 2001
From: practicalswift <practicalswift@users.noreply.github.com>
Date: Tue, 5 Dec 2017 23:00:43 +0100
Subject: [PATCH 1/2] Remove unused Python imports

---
 test/functional/example_test.py                  | 1 -
 test/functional/test_framework/messages.py       | 2 +-
 test/functional/test_framework/test_framework.py | 1 -
 3 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/test/functional/example_test.py b/test/functional/example_test.py
index 289fa248e0dbc..35a6bd26735d6 100755
--- a/test/functional/example_test.py
+++ b/test/functional/example_test.py
@@ -22,7 +22,6 @@
     mininode_lock,
     msg_block,
     msg_getdata,
-    NODE_NETWORK,
 )
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
diff --git a/test/functional/test_framework/messages.py b/test/functional/test_framework/messages.py
index eee24910cb67d..2ab1bdac0f735 100644
--- a/test/functional/test_framework/messages.py
+++ b/test/functional/test_framework/messages.py
@@ -24,7 +24,7 @@
 import time
 
 from test_framework.siphash import siphash256
-from test_framework.util import hex_str_to_bytes, bytes_to_hex_str, wait_until
+from test_framework.util import hex_str_to_bytes, bytes_to_hex_str
 
 MIN_VERSION_SUPPORTED = 60001
 MY_VERSION = 70014  # past bip-31 for ping/pong
diff --git a/test/functional/test_framework/test_framework.py b/test/functional/test_framework/test_framework.py
index 54fe689686001..a46312d62ce7f 100755
--- a/test/functional/test_framework/test_framework.py
+++ b/test/functional/test_framework/test_framework.py
@@ -13,7 +13,6 @@
 import sys
 import tempfile
 import time
-import traceback
 
 from .authproxy import JSONRPCException
 from . import coverage

From d60b32074098d50b04e408c1304dd6f6120654ed Mon Sep 17 00:00:00 2001
From: practicalswift <practicalswift@users.noreply.github.com>
Date: Tue, 5 Dec 2017 21:12:04 +0100
Subject: [PATCH 2/2] Add Travis check for unused Python imports

---
 .travis.yml                     |  3 ++-
 contrib/devtools/lint-python.sh | 10 ++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)
 create mode 100755 contrib/devtools/lint-python.sh

diff --git a/.travis.yml b/.travis.yml
index d3dd37e76c543..ab002acc539d9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -21,7 +21,7 @@ env:
     - WINEDEBUG=fixme-all
   matrix:
 # ARM
-    - HOST=arm-linux-gnueabihf PACKAGES="g++-arm-linux-gnueabihf" DEP_OPTS="NO_QT=1" CHECK_DOC=1 GOAL="install" BITCOIN_CONFIG="--enable-glibc-back-compat --enable-reduce-exports"
+    - HOST=arm-linux-gnueabihf PACKAGES="g++-arm-linux-gnueabihf python3-pip" DEP_OPTS="NO_QT=1" CHECK_DOC=1 GOAL="install" BITCOIN_CONFIG="--enable-glibc-back-compat --enable-reduce-exports"
 # Win32
     - HOST=i686-w64-mingw32 DPKG_ADD_ARCH="i386" DEP_OPTS="NO_QT=1" PACKAGES="python3 nsis g++-mingw-w64-i686 wine1.6" RUN_TESTS=true GOAL="install" BITCOIN_CONFIG="--enable-reduce-exports"
 # Qt4 & system libs
@@ -43,6 +43,7 @@ install:
     - if [ -n "$DPKG_ADD_ARCH" ]; then sudo dpkg --add-architecture "$DPKG_ADD_ARCH" ; fi
     - if [ -n "$PACKAGES" ]; then travis_retry sudo apt-get update; fi
     - if [ -n "$PACKAGES" ]; then travis_retry sudo apt-get install --no-install-recommends --no-upgrade -qq $PACKAGES; fi
+    - if [ "$CHECK_DOC" = 1 -a "$TRAVIS_EVENT_TYPE" = "pull_request" ]; then travis_retry pip3 install flake8 --user; fi
 before_script:
     - if [ "$CHECK_DOC" = 1 -a "$TRAVIS_EVENT_TYPE" = "pull_request" ]; then contrib/devtools/commit-script-check.sh $TRAVIS_COMMIT_RANGE; fi
     - if [ "$CHECK_DOC" = 1 ]; then contrib/devtools/git-subtree-check.sh src/crypto/ctaes; fi
diff --git a/contrib/devtools/lint-python.sh b/contrib/devtools/lint-python.sh
new file mode 100755
index 0000000000000..9303fcc8efeee
--- /dev/null
+++ b/contrib/devtools/lint-python.sh
@@ -0,0 +1,10 @@
+#!/bin/sh
+#
+# Copyright (c) 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.
+#
+# Check for specified flake8 warnings in python files.
+
+# F401: module imported but unused
+flake8 --ignore=B,C,E,F,I,N,W --select=F401 .