7
class OutputFormatter(object):
8
def __init__(self, outfile=sys.stdout):
17
self.outfile = outfile
19
def add_arguments(self, argument_parser):
20
formatgroup = argument_parser.add_mutually_exclusive_group()
21
choices = self.supported_formats
22
formatgroup.add_argument("--format", metavar='FMT',
23
help="Select output format for returned data, "
24
"where FMT is one of: {}".format(choices),
25
choices=choices, default='raw')
26
for fmt in self.formats:
27
fmtfunc = getattr(self, fmt)
28
formatgroup.add_argument("-{}".format(fmt[0]),
29
"--{}".format(fmt), action='store_const',
30
const=fmt, dest='format',
34
def supported_formats(self):
37
def raw(self, output):
38
"""Output data as raw string (default)"""
39
self.outfile.write(str(output))
42
"""Output data as a nicely-formatted python data structure"""
44
pprint.pprint(output, stream=self.outfile)
46
def json(self, output):
47
"""Output data in JSON format"""
49
json.dump(output, self.outfile)
51
def yaml(self, output):
52
"""Output data in YAML format"""
54
yaml.safe_dump(output, self.outfile)
56
def csv(self, output):
57
"""Output data as excel-compatible CSV"""
59
csvwriter = csv.writer(self.outfile)
60
csvwriter.writerows(output)
62
def tab(self, output):
63
"""Output data in excel-compatible tab-delimited format"""
65
csvwriter = csv.writer(self.outfile, dialect=csv.excel_tab)
66
csvwriter.writerows(output)
68
def format_output(self, output, fmt='raw'):
69
fmtfunc = getattr(self, fmt)
73
class CommandLine(object):
74
argument_parser = None
79
if not self.argument_parser:
80
self.argument_parser = argparse.ArgumentParser(description='Perform common charm tasks')
81
if not self.formatter:
82
self.formatter = OutputFormatter()
83
self.formatter.add_arguments(self.argument_parser)
84
if not self.subparsers:
85
self.subparsers = self.argument_parser.add_subparsers(help='Commands')
87
def subcommand(self, command_name=None):
89
Decorate a function as a subcommand. Use its arguments as the
90
command-line arguments"""
91
def wrapper(decorated):
92
cmd_name = command_name or decorated.__name__
93
subparser = self.subparsers.add_parser(cmd_name,
94
description=decorated.__doc__)
95
for args, kwargs in describe_arguments(decorated):
96
subparser.add_argument(*args, **kwargs)
97
subparser.set_defaults(func=decorated)
101
def subcommand_builder(self, command_name, description=None):
103
Decorate a function that builds a subcommand. Builders should accept a
104
single argument (the subparser instance) and return the function to be
105
run as the command."""
106
def wrapper(decorated):
107
subparser = self.subparsers.add_parser(command_name)
108
func = decorated(subparser)
109
subparser.set_defaults(func=func)
110
subparser.description = description or func.__doc__
114
"Run cli, processing arguments and executing subcommands."
115
arguments = self.argument_parser.parse_args()
116
argspec = inspect.getargspec(arguments.func)
120
vargs = getattr(arguments, argspec.varargs)
121
for arg in argspec.args:
122
kwargs[arg] = getattr(arguments, arg)
123
self.formatter.format_output(arguments.func(*vargs, **kwargs), arguments.format)
126
cmdline = CommandLine()
129
def describe_arguments(func):
131
Analyze a function's signature and return a data structure suitable for
132
passing in as arguments to an argparse parser's add_argument() method."""
134
argspec = inspect.getargspec(func)
135
# we should probably raise an exception somewhere if func includes **kwargs
137
positional_args = argspec.args[:-len(argspec.defaults)]
138
keyword_names = argspec.args[-len(argspec.defaults):]
139
for arg, default in itertools.izip(keyword_names, argspec.defaults):
140
yield ('--{}'.format(arg),), {'default': default}
142
positional_args = argspec.args
144
for arg in positional_args:
147
yield (argspec.varargs,), {'nargs': '*'}
added
removed
hooks/charmhelpers/cli/__init__.py
