flake8: paths

src/paths.py

@@ -1,76 +1,85 @@
-from os import environ, path
-import sys
+import logging
+import os
 import re
+import sys
 from datetime import datetime
+from shutil import move
+
+
+logger = logging.getLogger('default')
 
 # When using py2exe or py2app, the variable frozen is added to the sys
-# namespace.  This can be used to setup a different code path for 
+# namespace.  This can be used to setup a different code path for
 # binary distributions vs source distributions.
-frozen = getattr(sys,'frozen', None)
+frozen = getattr(sys, 'frozen', None)
+
 
 def lookupExeFolder():
+    """Returns executable folder path"""
     if frozen:
-        if frozen == "macosx_app":
+        exeFolder = (
             # targetdir/Bitmessage.app/Contents/MacOS/Bitmessage
-            exeFolder = path.dirname(path.dirname(path.dirname(path.dirname(sys.executable)))) + path.sep
-        else:
-            exeFolder = path.dirname(sys.executable) + path.sep
+            os.path.dirname(sys.executable).split(os.path.sep)[0] + os.path.sep
+            if frozen == "macosx_app" else
+            os.path.dirname(sys.executable) + os.path.sep)
     elif __file__:
-        exeFolder = path.dirname(__file__) + path.sep
+        exeFolder = os.path.dirname(__file__) + os.path.sep
     else:
         exeFolder = ''
     return exeFolder
 
+
 def lookupAppdataFolder():
+    """Returns path of the folder where application data is stored"""
     APPNAME = "PyBitmessage"
-    if "BITMESSAGE_HOME" in environ:
-        dataFolder = environ["BITMESSAGE_HOME"]
-        if dataFolder[-1] not in [path.sep, path.altsep]:
-            dataFolder += path.sep
+    dataFolder = os.environ.get('BITMESSAGE_HOME')
+    if dataFolder:
+        if dataFolder[-1] not in (os.path.sep, os.path.altsep):
+            dataFolder += os.path.sep
     elif sys.platform == 'darwin':
-        if "HOME" in environ:
-            dataFolder = path.join(environ["HOME"], "Library/Application Support/", APPNAME) + '/'
-        else:
-            stringToLog = 'Could not find home folder, please report this message and your OS X version to the BitMessage Github.'
-            if 'logger' in globals():
-                logger.critical(stringToLog)
-            else:
-                print stringToLog
-            sys.exit()
-
+        try:
+            dataFolder = os.path.join(
+                os.environ['HOME'],
+                'Library/Application Support/', APPNAME
+            ) + '/'  # FIXME: should also be os.path.sep
+        except KeyError:
+            sys.exit(
+                'Could not find home folder, please report this message'
+                ' and your OS X version to the BitMessage Github.')
     elif 'win32' in sys.platform or 'win64' in sys.platform:
-        dataFolder = path.join(environ['APPDATA'].decode(sys.getfilesystemencoding(), 'ignore'), APPNAME) + path.sep
+        dataFolder = os.path.join(
+            os.environ['APPDATA'].decode(
+                sys.getfilesystemencoding(), 'ignore'), APPNAME
+        ) + os.path.sep
     else:
-        from shutil import move
         try:
-            dataFolder = path.join(environ["XDG_CONFIG_HOME"], APPNAME)
+            dataFolder = os.path.join(os.environ['XDG_CONFIG_HOME'], APPNAME)
         except KeyError:
-            dataFolder = path.join(environ["HOME"], ".config", APPNAME)
+            dataFolder = os.path.join(os.environ['HOME'], '.config', APPNAME)
 
-        # Migrate existing data to the proper location if this is an existing install
+        # Migrate existing data to the proper location
+        # if this is an existing install
         try:
-            move(path.join(environ["HOME"], ".%s" % APPNAME), dataFolder)
-            stringToLog = "Moving data folder to %s" % (dataFolder)
-            if 'logger' in globals():
-                logger.info(stringToLog)
-            else:
-                print stringToLog
+            move(os.path.join(os.environ['HOME'], '.%s' % APPNAME), dataFolder)
+            logger.info('Moving data folder to %s', dataFolder)
         except IOError:
             # Old directory may not exist.
             pass
-        dataFolder = dataFolder + '/'
+        dataFolder = dataFolder + os.path.sep
     return dataFolder
-    
+
+
 def codePath():
-    if frozen == "macosx_app":
-        codePath = environ.get("RESOURCEPATH")
-    elif frozen: # windows
-        codePath = sys._MEIPASS
-    else:    
-        codePath = path.dirname(__file__)
-    return codePath
+    """Returns path to the program sources"""
+    if not frozen:
+        return os.path.dirname(__file__)
+    return (
+        os.environ.get('RESOURCEPATH')
+        if frozen == "macosx_app" else sys._MEIPASS)
+
 
 def tail(f, lines=20):
+    """Returns last lines in the f file object"""
     total_lines_wanted = lines
 
     BLOCK_SIZE = 1024
@@ -78,16 +87,17 @@ def tail(f, lines=20):
     block_end_byte = f.tell()
     lines_to_go = total_lines_wanted
     block_number = -1
-    blocks = [] # blocks of size BLOCK_SIZE, in reverse order starting
-                # from the end of the file
+    # blocks of size BLOCK_SIZE, in reverse order starting
+    # from the end of the file
+    blocks = []
     while lines_to_go > 0 and block_end_byte > 0:
         if (block_end_byte - BLOCK_SIZE > 0):
             # read the last block we haven't yet read
-            f.seek(block_number*BLOCK_SIZE, 2)
+            f.seek(block_number * BLOCK_SIZE, 2)
             blocks.append(f.read(BLOCK_SIZE))
         else:
             # file too small, start from begining
-            f.seek(0,0)
+            f.seek(0, 0)
             # only read what was not read
             blocks.append(f.read(block_end_byte))
         lines_found = blocks[-1].count('\n')
@@ -99,9 +109,12 @@ def tail(f, lines=20):
 
 
 def lastCommit():
-    githeadfile = path.join(codePath(), '..', '.git', 'logs', 'HEAD')
+    """
+    Returns last commit information as dict with 'commit' and 'time' keys
+    """
+    githeadfile = os.path.join(codePath(), '..', '.git', 'logs', 'HEAD')
     result = {}
-    if path.isfile(githeadfile):
+    if os.path.isfile(githeadfile):
         try:
             with open(githeadfile, 'rt') as githead:
                 line = tail(githead, 1)