Move code of main script under __main__ condition

Multiprocessing on Windows does full copy of module and this would lead
to the re-execution of this code.

Posibly fixes #33.

setup.py

@@ -8,7 +8,7 @@
 
 setup(
   name='ulozto-downloader',
-  version='1.5.1',
+  version='1.5.2',
   license='MIT',
   description='Uloz.to quick multiple sessions downloader.',
   long_description=long_description,

ulozto-downloader

@@ -7,34 +7,35 @@ import signal
 
 from ulozto_downloader import downloader, captcha
 
-parser = argparse.ArgumentParser(
-    description='Download file from Uloz.to using multiple parallel downloads.',
-    formatter_class=argparse.ArgumentDefaultsHelpFormatter,
-)
-parser.add_argument('url', metavar='URL', type=str, help="URL from Uloz.to (tip: enter in 'quotes' because the URL contains ! sign)")
-parser.add_argument('--parts', metavar='N', type=int, default=10, help='Number of parts that will be downloaded in parallel')
-parser.add_argument('--output', metavar='DIRECTORY', type=str, default="./", help='Target directory')
-parser.add_argument('--auto-captcha', default=False, action="store_true", help='Try to solve captchas automatically using TensorFlow')
 
-args = parser.parse_args()
-
-if args.auto_captcha:
-    model_path = "model.tflite"
-    model_download_url = "https://github.com/JanPalasek/ulozto-captcha-breaker/releases/download/v2.2/model.tflite"
-    captcha_solve_fnc = captcha.AutoReadCaptcha(model_path, model_download_url)
-else:
-    captcha_solve_fnc = captcha.tkinter_user_prompt
-
-d = downloader.Downloader(captcha_solve_fnc)
-
-
-# Register sigint handler
 def sigint_handler(sig, frame):
     d.terminate()
     print('Program terminated.')
     sys.exit(1)
 
 
-signal.signal(signal.SIGINT, sigint_handler)
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(
+        description='Download file from Uloz.to using multiple parallel downloads.',
+        formatter_class=argparse.ArgumentDefaultsHelpFormatter,
+    )
+    parser.add_argument('url', metavar='URL', type=str, help="URL from Uloz.to (tip: enter in 'quotes' because the URL contains ! sign)")
+    parser.add_argument('--parts', metavar='N', type=int, default=10, help='Number of parts that will be downloaded in parallel')
+    parser.add_argument('--output', metavar='DIRECTORY', type=str, default="./", help='Target directory')
+    parser.add_argument('--auto-captcha', default=False, action="store_true", help='Try to solve captchas automatically using TensorFlow')
+
+    args = parser.parse_args()
+
+    if args.auto_captcha:
+        model_path = "model.tflite"
+        model_download_url = "https://github.com/JanPalasek/ulozto-captcha-breaker/releases/download/v2.2/model.tflite"
+        captcha_solve_fnc = captcha.AutoReadCaptcha(model_path, model_download_url)
+    else:
+        captcha_solve_fnc = captcha.tkinter_user_prompt
+
+    d = downloader.Downloader(captcha_solve_fnc)
+
+    # Register sigint handler
+    signal.signal(signal.SIGINT, sigint_handler)
 
-d.download(args.url, args.parts, args.output)
+    d.download(args.url, args.parts, args.output)