def _DisplayError(component_trace):
"""Prints the Fire trace and the error to stdout."""
output = []
for help_flag in ('-h', '--help'):
if help_flag in component_trace.elements[-1].args:
command = '{cmd} -- --help'.format(
cmd=component_trace.GetCommand())
message = 'INFO: Showing help with the command {cmd}.\n'.format(
cmd=pipes.quote(command))
output.append(message)
output.append(
formatting.Error('ERROR: ') +
component_trace.elements[-1].ErrorAsStr())
result = component_trace.GetResult()
help_string = helptext.HelpString(result, component_trace,
component_trace.verbose)
output.append(help_string)
Display(output)
def _PrintResult(component_trace, verbose=False):
"""Prints the result of the Fire call to stdout in a human readable way."""
# TODO(dbieber): Design human readable deserializable serialization method
# and move serialization to its own module.
result = component_trace.GetResult()
if isinstance(result, (list, set, types.GeneratorType)):
for i in result:
print(_OneLineResult(i))
elif inspect.isgeneratorfunction(result):
raise NotImplementedError
elif isinstance(result, dict):
print(_DictAsString(result, verbose))
elif isinstance(result, tuple):
print(_OneLineResult(result))
elif isinstance(result, value_types.VALUE_TYPES):
print(result)
elif result is not None:
print(helptext.HelpString(result, component_trace, verbose))
def Fire(component=None, command=None, name=None):
"""This function, Fire, is the main entrypoint for Python Fire.
Executes a command either from the `command` argument or from sys.argv by
recursively traversing the target object `component`'s members consuming
arguments, evaluating functions, and instantiating classes as it goes.
When building a CLI with Fire, your main method should call this function.
Args:
component: The initial target component.
command: Optional. If supplied, this is the command executed. If not
supplied, then the command is taken from sys.argv instead. This can be
a string or a list of strings; a list of strings is preferred.
name: Optional. The name of the command as entered at the command line.
Used in interactive mode and for generating the completion script.
Returns:
The result of executing the Fire command. Execution begins with the initial
target component. The component is updated by using the command arguments
to either access a member of the current component, call the current
component (if it's a function), or instantiate the current component (if
it's a class). When all arguments are consumed and there's no function left
to call or class left to instantiate, the resulting current component is
the final result.
Raises:
ValueError: If the command argument is supplied, but not a string or a
sequence of arguments.
FireExit: When Fire encounters a FireError, Fire will raise a FireExit with
code 2. When used with the help or trace flags, Fire will raise a
FireExit with code 0 if successful.
"""
name = name or os.path.basename(sys.argv[0])
# Get args as a list.
if isinstance(command, six.string_types):
args = shlex.split(command)
elif isinstance(command, (list, tuple)):
args = command
elif command is None:
# Use the command line args by default if no command is specified.
args = sys.argv[1:]
else:
raise ValueError(
'The command argument must be a string or a sequence of '
'arguments.')
args, flag_args = parser.SeparateFlagArgs(args)
argparser = parser.CreateParser()
parsed_flag_args, unused_args = argparser.parse_known_args(flag_args)
context = {}
if parsed_flag_args.interactive or component is None:
# Determine the calling context.
caller = inspect.stack()[1]
caller_frame = caller[0]
caller_globals = caller_frame.f_globals
caller_locals = caller_frame.f_locals
context.update(caller_globals)
context.update(caller_locals)
component_trace = _Fire(component, args, parsed_flag_args, context, name)
if component_trace.HasError():
_DisplayError(component_trace)
raise FireExit(2, component_trace)
if component_trace.show_trace and component_trace.show_help:
output = ['Fire trace:\n{trace}\n'.format(trace=component_trace)]
result = component_trace.GetResult()
help_string = helptext.HelpString(result, component_trace,
component_trace.verbose)
output.append(help_string)
Display(output)
raise FireExit(0, component_trace)
if component_trace.show_trace:
output = ['Fire trace:\n{trace}'.format(trace=component_trace)]
Display(output)
raise FireExit(0, component_trace)
if component_trace.show_help:
result = component_trace.GetResult()
help_string = helptext.HelpString(result, component_trace,
component_trace.verbose)
output = [help_string]
Display(output)
raise FireExit(0, component_trace)
# The command succeeded normally; print the result.
_PrintResult(component_trace, verbose=component_trace.verbose)
result = component_trace.GetResult()
return result