Travis CI: Add flake8 tests for syntax errors and undefined names

.travis.yml

@@ -10,21 +10,27 @@ python:
 
 matrix:
   include:
-  - python 3.7
-    dist: xenial    # required for Python 3.7 (travis-ci/travis-ci#9069)
-    sudo: required  # required for Python 3.7 (travis-ci/travis-ci#9069)
+    - python: 3.7
+      dist: xenial    # required for Python 3.7 (travis-ci/travis-ci#9069)
+      sudo: required  # required for Python 3.7 (travis-ci/travis-ci#9069)
   allow_failures:
     # PyPy on Travis is currently incompatible with Cryptography.
     - python: pypy
 
 install:
   - export PYTHONIOENCODING=UTF8
-  - pip install coveralls pytest-cov ptyprocess
+  - pip install coveralls flake8 pytest-cov ptyprocess
+
+before_script:
+  # stop the build if there are Python syntax errors or undefined names
+  - flake8 . --count --exclude=./tests --select=E901,E999,F821,F822,F823 --show-source --statistics
+  # exit-zero treats all errors as warnings.  The GitHub editor is 127 chars wide
+  - flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
 
 script:
-    - ./tools/display-sighandlers.py
-    - ./tools/display-terminalinfo.py
-    - py.test --cov pexpect --cov-config .coveragerc
+  - ./tools/display-sighandlers.py
+  - ./tools/display-terminalinfo.py
+  - py.test --cov pexpect --cov-config .coveragerc
 
 after_success:
   - coverage combine

examples/chess.py

@@ -145,4 +145,7 @@ def quit(self):
     white.do_move (move_black)
     print('tail of loop')
 
-g.quit()
+try:
+    g.quit()
+except NameError:
+    pass

examples/chess2.py

@@ -148,6 +148,7 @@ def LOG (s):
 
     white.do_move (move_black, 1)
 
-g.quit()
-
-
+try:
+    g.quit()
+except NameError:
+    pass

examples/chess3.py

@@ -154,4 +154,7 @@ def quit(self):
     white.do_move (move_black)
     print('tail of loop')
 
-g.quit()
+try:
+    g.quit()
+except NameError:
+    pass

examples/hive.py

@@ -216,7 +216,7 @@ def login (args, cli_username=None, cli_password=None):
     for hostname in host_names:
         print('connecting to', hostname)
         try:
-            fout = file("log_"+hostname, "w")
+            fout = open("log_"+hostname, "w")
             hive[hostname] = pxssh.pxssh()
             # Disable host key checking.
             hive[hostname].SSH_OPTS = (hive[hostname].SSH_OPTS

examples/monitor.py

@@ -223,7 +223,8 @@ def main():
     index = child.expect([pexpect.EOF, "(?i)there are stopped jobs"])
     if index==1:
         child.sendline("exit")
-        child.expect(EOF)
+        child.expect(pexpect.EOF)
+
 
 if __name__ == "__main__":
     main()

examples/passmass.py

@@ -45,7 +45,7 @@
 def login(host, user, password):
 
     child = pexpect.spawn('ssh -l %s %s'%(user, host))
-    fout = file ("LOG.TXT","wb")
+    fout = open("LOG.TXT","wb")
     child.logfile_read = fout #use child.logfile to also log writes (passwords!)
 
     i = child.expect([pexpect.TIMEOUT, SSH_NEWKEY, '[Pp]assword: '])

examples/topip.py

@@ -267,7 +267,7 @@ def main():
 
     # load the stats from the last run.
     try:
-        last_stats = pickle.load(file(TOPIP_LAST_RUN_STATS))
+        last_stats = pickle.load(open(TOPIP_LAST_RUN_STATS))
     except:
         last_stats = {'maxip':None}
 
@@ -280,7 +280,7 @@ def main():
                     % hostname, alert_addr_from, alert_addr_to)
         if log_flag:
             if verbose: print('LOGGING THIS EVENT')
-            fout = file(TOPIP_LOG_FILE,'a')
+            fout = open(TOPIP_LOG_FILE,'a')
             #dts = time.strftime('%Y:%m:%d:%H:%M:%S', time.localtime())
             dts = time.asctime()
             fout.write ('%s - %d connections from %s\n'
@@ -289,7 +289,7 @@ def main():
 
     # save state to TOPIP_LAST_RUN_STATS
     try:
-        pickle.dump(s, file(TOPIP_LAST_RUN_STATS,'w'))
+        pickle.dump(s, open(TOPIP_LAST_RUN_STATS,'w'))
         os.chmod (TOPIP_LAST_RUN_STATS, 0o664)
     except:
         pass

notes/my_forkpty.py

@@ -1,6 +1,10 @@
+from __future__ import print_function
 import os, fcntl, termios
 import time
 
+from pexpect import ExceptionPexpect
+
+
 def my_forkpty():
 
     (master_fd, slave_fd) = os.openpty()
@@ -80,10 +84,9 @@ def my_forkpty():
 
 pid, fd = my_forkpty ()
 if pid == 0: # child
-    print 'I am not a robot!'
+    print('I am not a robot!')
 else:
-    print '(pid, fd) = (%d, %d)' % (pid, fd)
+    print('(pid, fd) = (%d, %d)' % (pid, fd))
     time.sleep(1) # Give the child a chance to print.
-    print 'Robots always say:', os.read(fd,100)
+    print('Robots always say:', os.read(fd,100))
     os.close(fd)
-

pexpect/FSM.py

@@ -326,7 +326,10 @@ def main():
     print('Use the = sign to evaluate and print the expression.')
     print('For example: ')
     print('    167 3 2 2 * * * 1 - =')
-    inputstr = (input if PY3 else raw_input)('> ')  # analysis:ignore
+    try:
+        inputstr = raw_input('> ')
+    except NameError:
+        inputstr = input('> ')
     f.process_list(inputstr)
 
 

pexpect/_async.py

@@ -1,3 +1,6 @@
+# flake8: noqa This file is Python 3-only and async yield is a Py2 syntax error
+# TODO: Remove these two lines when support for legacy Python is dropped.
+
 import asyncio
 import errno
 import signal

pexpect/spawnbase.py

@@ -8,7 +8,11 @@
 from .expect import Expecter, searcher_string, searcher_re
 
 PY3 = (sys.version_info[0] >= 3)
-text_type = str if PY3 else unicode
+try:
+    text_type = unicode
+except NameError:
+    text_type = str
+
 
 class _NullCoder(object):
     """Pass bytes through unchanged."""
@@ -88,7 +92,11 @@ def __init__(self, timeout=30, maxread=2000, searchwindowsize=None,
             self.string_type = bytes
             self.buffer_type = BytesIO
             self.crlf = b'\r\n'
-            if PY3:
+            try:               # Python 2
+                self.allowed_string_types = (basestring, )
+                self.linesep = os.linesep
+                self.write_to_stdout = sys.stdout.write
+            except NameError:  # Python 3
                 self.allowed_string_types = (bytes, str)
                 self.linesep = os.linesep.encode('ascii')
                 def write_to_stdout(b):
@@ -98,10 +106,7 @@ def write_to_stdout(b):
                         # If stdout has been replaced, it may not have .buffer
                         return sys.stdout.write(b.decode('ascii', 'replace'))
                 self.write_to_stdout = write_to_stdout
-            else:
-                self.allowed_string_types = (basestring,)  # analysis:ignore
-                self.linesep = os.linesep
-                self.write_to_stdout = sys.stdout.write
+
         else:
             # unicode mode
             self._encoder = codecs.getincrementalencoder(encoding)(codec_errors)

pexpect/utils.py

@@ -11,10 +11,10 @@
     # Alias Python2 exception to Python3
     InterruptedError = select.error
 
-if sys.version_info[0] >= 3:
-    string_types = (str,)
-else:
+try:
     string_types = (unicode, str)
+except NameError:
+    string_types = (str,)
 
 
 def is_executable_file(path):

tests/platform_checks/check.py

@@ -1,9 +1,11 @@
 #!/usr/bin/env python
-import signal
 import os
+import signal
+import sys
 import time
 import pty
 
+
 def signal_handler (signum, frame):
     print 'Signal handler called with signal:', signum
     print 'signal.SIGCHLD=', signal.SIGKILL
@@ -74,4 +76,3 @@ def signal_handler (signum, frame):
     print 'Child is alive. This is ambiguous because it may be a Zombie.'
 except OSError as e:
     print 'Child appears to be dead.'
-

tests/platform_checks/check_read.py

@@ -31,5 +31,5 @@
 		break
 os.close(fd_in)
 d = os.read(fd_in, 1) # fd_in should be closed now...
-if s == '':
+if d == '':
 	print 'd is empty. good.'

tests/test_run_out_of_pty.py

@@ -19,6 +19,7 @@
 
 '''
 import pexpect
+import sys
 import unittest
 from . import PexpectTestCase