v4.5.1 Issue #39 Use script path to locate data directory.

When starting up, change current directory to match the path of trade.py
- so if you do "trade/trade.py" it will look for "trade/data/..."

Also added --dir (aka -C) to change directory

README.txt

@@ -23,6 +23,14 @@ files from other commanders to fill out your database.
 == CHANGE LOG
 ==============================================================================
 
+v4.5.1 Oct 20/2014
+. (kfsone) Added --dir (-C) command line for specifying which directory you
+  want trade.py to look in for it's files.
+. (kfsone) trade.py will now default to trying to look for files relative
+  to where the "trade.py" script was called from. So if you run
+  "c:\tradedangerous\trade.py" it will look for the data directory as
+  "c:\tradedangerous\data\" (Issue #39)
+
 v4.5.0 Oct 20/2014
 . (Smacker65/Community) Smacker brings the star database up to 567 systems.
 

trade.py

@@ -924,6 +924,7 @@ def main():
     commonArgs.add_argument('--detail', '-v', help='Increase level  of detail in output.', default=0, required=False, action='count')
     commonArgs.add_argument('--quiet',  '-q', help='Reduce level of detail in output.', default=0, required=False, action='count')
     commonArgs.add_argument('--db', help='Specify location of the SQLite database. Default: {}'.format(TradeDB.defaultDB), type=str, default=str(TradeDB.defaultDB))
+    commonArgs.add_argument('--cwd',    '-C', help='Change the directory relative to which TradeDangerous will try to access files such as the .db, etc.', type=str, required=False)
 
     subparsers = parser.add_subparsers(dest='subparser', title='Commands')
 
@@ -1019,6 +1020,18 @@ def main():
     if args.detail and args.quiet:
         raise CommandLineError("'--detail' (-v) and '--quiet' (-q) are mutually exclusive.")
 
+    # If a directory was specified, relocate to it.
+    # Otherwise, try to chdir to 
+    if args.dir:
+        os.chdir(args.dir)
+    else:
+        if sys.argv[0]:
+            cwdPath = pathlib.Path('.').resolve()
+            exePath = pathlib.Path(sys.argv[0]).parent.resolve()
+            if cwdPath != exePath:
+                if args.debug: print("# cwd at launch was: {}, changing to {} to match trade.py".format(cwdPath, exePath))
+                os.chdir(str(exePath))
+
     # load the database
     tdb = TradeDB(debug=args.debug, dbFilename=args.db)