Add command line options to show version number

Add -V command line option (and --version as an alias) to
both wireviz.py and build_examples.py that show version number.

Move the version number from setup.py into __init__.py to access
the same version number specification from all files needing it.

This solves part 4 of issue #167.

setup.py

@@ -4,6 +4,8 @@
 import os
 from setuptools import setup, find_packages
 
+from src.wireviz import __version__
+
 project_name = 'wireviz'
 
 # Utility function to read the README file.
@@ -15,7 +17,7 @@ def read(fname):
 
 setup(
     name=project_name,
-    version='0.1',
+    version=__version__,
     author='Daniel Rojas',
     #author_email='',
     description='Easily document cables and wiring harnesses',

src/wireviz/__init__.py

@@ -0,0 +1,3 @@
+# Please don't import anything in this file to avoid issues when it is imported in setup.py
+
+__version__ = '0.1.1'

src/wireviz/build_examples.py

@@ -9,7 +9,7 @@ from pathlib import Path
 script_path = Path(__file__).absolute()
 
 sys.path.insert(0, str(script_path.parent.parent))  # to find wireviz module
-from wireviz import wireviz
+from wireviz import wireviz, __version__
 from wv_helper import open_file_write, open_file_read, open_file_append
 
 
@@ -128,6 +128,7 @@ def restore_generated(groupkeys, branch = ''):
 
 def parse_args():
     parser = argparse.ArgumentParser(description='Wireviz Example Manager',)
+    parser.add_argument('-V', '--version', action='version', version='%(prog)s - wireviz ' + __version__)
     parser.add_argument('action', nargs='?', action='store',
                         choices=['build','clean','compare','diff','restore'], default='build',
                         help='what to do with the generated files (default: build)')

src/wireviz/wireviz.py

@@ -12,7 +12,7 @@ import yaml
 if __name__ == '__main__':
     sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..'))
 
-
+from wireviz import __version__
 from wireviz.Harness import Harness
 from wireviz.wv_helper import expand, open_file_read
 
@@ -211,6 +211,7 @@ def parse_cmdline():
     parser = argparse.ArgumentParser(
         description='Generate cable and wiring harness documentation from YAML descriptions',
     )
+    parser.add_argument('-V', '--version', action='version', version='%(prog)s ' + __version__)
     parser.add_argument('input_file', action='store', type=str, metavar='YAML_FILE')
     parser.add_argument('-o', '--output_file', action='store', type=str, metavar='OUTPUT')
     # Not implemented: parser.add_argument('--generate-bom', action='store_true', default=True)