From: W. Trevor King <wking@drexel.edu>
Date: Mon, 19 Mar 2012 18:51:40 +0000 (-0400)
Subject: Consolidate demo argument parsing in pycomedi_demo_args.py to reduce duplication.
X-Git-Tag: 0.5~22
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=7bb319f9e641f76ecb69fd729ec6d40ec2eb8042;p=pycomedi.git

Consolidate demo argument parsing in pycomedi_demo_args.py to reduce duplication.
---

diff --git a/doc/demo/cmd.py b/doc/demo/cmd.py
index 6d16bff..3ee20fd 100755
--- a/doc/demo/cmd.py
+++ b/doc/demo/cmd.py
@@ -11,7 +11,6 @@ by on-board timers or external events.
 Based on David A. Schleef's `comedilib/demo/cmd.c`.
 """
 
-import logging as _logging
 import sys as _sys
 import time as _time
 
@@ -103,62 +102,24 @@ def read(device, subdevice=None, channels=[0], range=0, aref=0, period=0,
 
 
 if __name__ == '__main__':
-    import argparse
-
-    parser = argparse.ArgumentParser(description=__doc__)
-    parser.add_argument(
-        '-f', '--filename', default='/dev/comedi0',
-        help='path to comedi device file')
-    parser.add_argument(
-        '-s', '--subdevice', type=int, help='subdevice for analog input')
-    parser.add_argument(
-        '-c', '--channel', type=int, action='append',
-        help='add a channel for analog input')
-    parser.add_argument(
-        '-a', '--analog-reference', dest='aref', default='ground',
-        choices=['diff', 'ground', 'other', 'common'],
-        help='reference for analog input')
-    parser.add_argument(
-        '-r', '--range', type=int, default=0, help='range for analog input')
-    parser.add_argument(
-        '-N', '--num-scans', type=int, default=10,
-        help='number of analog input scans')
-    parser.add_argument(
-        '-F', '--frequency', type=float, help='scan frequency in hertz')
-    parser.add_argument(
-        '-p', '--physical', default=False, action='store_const', const=True,
-        help='convert input to physical values before printing')
-    parser.add_argument(
-        '-v', '--verbose', default=0, action='count')
-
-    args = parser.parse_args()
-
-    if args.verbose >= 3:
-        _LOG.setLevel(_logging.DEBUG)
-    elif args.verbose >= 2:
-        _LOG.setLevel(_logging.INFO)
-    elif args.verbose >= 1:
-        _LOG.setLevel(_logging.WARN)
+    import pycomedi_demo_args
+
+    args = pycomedi_demo_args.parse_args(
+        description=__doc__,
+        argnames=['filename', 'subdevice', 'channels', 'aref', 'range', 'num-scans',
+                  'frequency', 'physical', 'verbose'])
 
     _LOG.info(('measuring device={0.filename} subdevice={0.subdevice} '
-               'channel={0.channel} range={0.range} analog reference={0.aref}'
+               'channels={0.channels} range={0.range} '
+               'analog-reference={0.aref}'
                ).format(args))
 
-    channel_indexes = args.channel
-    if not channel_indexes:
-        channel_indexes = [0]  # user gave no channels on the command line
-    aref = _constant.AREF.index_by_name(args.aref)
-    if args.frequency is None:
-        period = 0
-    else:
-        period = 1/args.frequency
-
     device = _Device(filename=args.filename)
     device.open()
     try:
         read(
-            device=device, subdevice=args.subdevice,
-            channels=channel_indexes, range=args.range, aref=aref,
-            period=period, num_scans=args.num_scans, physical=args.physical)
+            device=device, subdevice=args.subdevice, channels=args.channels,
+            range=args.range, aref=args.aref, period=args.period,
+            num_scans=args.num_scans, physical=args.physical)
     finally:
         device.close()
diff --git a/doc/demo/info.py b/doc/demo/info.py
index 552bd8a..5acded8 100755
--- a/doc/demo/info.py
+++ b/doc/demo/info.py
@@ -95,14 +95,9 @@ def display(device):
 
 
 if __name__ == '__main__':
-    import argparse
+    import pycomedi_demo_args
 
-    parser = argparse.ArgumentParser(description=__doc__)
-    parser.add_argument(
-        '-f', '--filename', default='/dev/comedi0',
-        help='path to comedi device file')
-
-    args = parser.parse_args()
+    args = pycomedi_demo_args.parse_args(description=__doc__, argnames=['filename'])
 
     device = _Device(filename=args.filename)
     device.open()
diff --git a/doc/demo/insn.py b/doc/demo/insn.py
index 9fc1001..52133cf 100755
--- a/doc/demo/insn.py
+++ b/doc/demo/insn.py
@@ -8,8 +8,6 @@ Do a ``gettimeofday()`` call, read some samples from an analog
 input, and do another ``gettimeofday()`` call.
 """
 
-import logging as _logging
-
 from pycomedi import LOG as _LOG
 import pycomedi.constant as _constant
 from pycomedi.device import Device as _Device
@@ -18,36 +16,12 @@ from pycomedi.chanspec import ChanSpec as _ChanSpec
 
 if __name__ == '__main__':
     import argparse
+    import pycomedi_demo_args
 
-    parser = argparse.ArgumentParser(description=__doc__)
-    parser.add_argument(
-        '-f', '--filename', default='/dev/comedi0',
-        help='path to comedi device file')
-    parser.add_argument(
-        '-s', '--subdevice', type=int, help='subdevice for analog input')
-    parser.add_argument(
-        '-c', '--channel', type=int, default=0,
-        help='channel for analog input')
-    parser.add_argument(
-        '-a', '--analog-reference', dest='aref', default='ground',
-        choices=['diff', 'ground', 'other', 'common'],
-        help='reference for analog input')
-    parser.add_argument(
-        '-r', '--range', type=int, default=0, help='range for analog input')
-    parser.add_argument(
-        '-N', '--num-scans', type=int, default=10,
-        help='number of analog input scans')
-    parser.add_argument(
-        '-v', '--verbose', default=0, action='count')
-
-    args = parser.parse_args()
-
-    if args.verbose >= 3:
-        _LOG.setLevel(_logging.DEBUG)
-    elif args.verbose >= 2:
-        _LOG.setLevel(_logging.INFO)
-    elif args.verbose >= 1:
-        _LOG.setLevel(_logging.WARN)
+    args = pycomedi_demo_args.parse_args(
+        description=__doc__,
+        argnames=['filename', 'subdevice', 'channel', 'aref', 'range', 'num-scans',
+                  'verbose'])
 
     _LOG.info(('measuring device={0.filename} subdevice={0.subdevice} '
                'channel={0.channel} range={0.range} analog reference={0.aref}'
@@ -65,18 +39,16 @@ if __name__ == '__main__':
     insns[0].data = insns[2].data = [0, 0]
     insns[1].insn = _constant.INSN.read
     insns[1].data = [0] * args.num_scans
-    aref = _constant.AREF.index_by_name(args.aref)
     insns[1].chanspec = _ChanSpec(
-        chan=args.channel, range=args.range, aref=aref)
+        chan=args.channel, range=args.range, aref=args.aref)
 
     device.do_insnlist(insns)
     device.close()
 
     t1 = insns[0].data[0] + insns[1].data[1]/1e6
     t2 = insns[2].data[0] + insns[2].data[1]/1e6
-    print('initial time: {}'.format(t1))
-    print('final time:   {}'.format(t2))
-    print('difference:   {}'.format(t2-t1))
-    print('data:')
+    _LOG.info('initial time: {}'.format(t1))
+    _LOG.info('final time:   {}'.format(t2))
+    _LOG.info('difference:   {}'.format(t2-t1))
     for x in insns[1].data:
         print(x)
diff --git a/doc/demo/pycomedi_demo_args.py b/doc/demo/pycomedi_demo_args.py
new file mode 100644
index 0000000..83f9f5d
--- /dev/null
+++ b/doc/demo/pycomedi_demo_args.py
@@ -0,0 +1,83 @@
+# Copyright
+
+import argparse as _argparse
+import logging as _logging
+
+from pycomedi import LOG as _LOG
+import pycomedi.constant as _constant
+
+
+class _SetFrequencyAction (_argparse.Action):
+    def __call__(self, parser, namespace, values, option_string=None):
+        setattr(namespace, self.dest, values)
+        setattr(namespace, 'period', 1.0/values)
+
+
+class _IncrementVerbosityAction (_argparse.Action):
+    def __call__(self, parser, namespace, values, option_string=None):
+        level = _LOG.level
+        level -= 10  # e.g. logging.INFO -> logging.DEBUG
+        if level >= _logging.DEBUG:
+            _LOG.setLevel(level)
+
+
+# name -> (args, kwargs)
+ARGUMENTS = {
+    'filename':(
+        ['-f', '--filename'],
+        {'default':'/dev/comedi0',
+         'help':'path to comedi device file'}),
+    'subdevice':(
+        ['-s', '--subdevice'],
+        {'type':int,
+         'help':'subdevice for analog input/output'}),
+    'channel':(
+        ['-c', '--channel'],
+        {'type':int,
+         'default':0,
+         'help':'channel for analog input/output'}),
+    'channels':(
+        ['-c', '--channels'],
+        {'type':lambda x: [int(i) for i in x.split(',')],
+         'default':0,
+         'help':'comma-separated channels for analog input/output'}),
+    'aref':(
+        ['-a', '--analog-reference'],
+        {'dest':'aref',
+         'default':_constant.AREF.ground,
+         'type':lambda x: _constant.AREF.index_by_name(x),
+         'choices':_constant.AREF,
+         'help':'reference for analog input/output'}),
+    'range':(
+        ['-r', '--range'],
+        {'type':int,
+         'default':0,
+         'help':'range for analog input/output'}),
+    'num-scans':(
+        ['-N', '--num-scans'],
+        {'type':int,
+         'default':10,
+         'help':'number of input/output scans'}),
+    'frequency':(
+        ['-F', '--frequency'],
+        {'type':float,
+         'action':_SetFrequencyAction,
+         'help':'scan frequency in hertz'}),
+    'physical':(
+        ['-p', '--physical'],
+        {'default':False,
+         'action':'store_const',
+         'const':True,
+         'help':'convert input to physical values before printing'}),
+    'verbose':(
+        ['-v', '--verbose'],
+        {'action':_IncrementVerbosityAction}),
+    }
+
+def parse_args(description, argnames):
+    parser = _argparse.ArgumentParser(description=description)
+    for argument in ['filename', 'subdevice', 'channels', 'aref', 'range',
+                     'num-scans', 'frequency', 'physical', 'verbose']:
+        args,kwargs = ARGUMENTS[argument]
+        parser.add_argument(*args, **kwargs)
+    return parser.parse_args()