Add a Python command-line interface (#441)

* In Python, delete the temporary file by default

* Add a Python command-line interface

* Apply style fixes

Signed-off-by: Ian Hunter <ian.hunter@intel.com>

* more style fixes

* fix trailing whitespace

---------

Signed-off-by: Ian Hunter <ian.hunter@intel.com>
Co-authored-by: Ian Hunter <ian.hunter@intel.com>

README.md

@@ -83,6 +83,15 @@ roll("1d20")
 # (return code, final result, dice breakdown (if enabled))
 ```
 
+Or, use the command-line interface (see `--help`):
+```sh
+$ python3 -m gnoll 2d4
+6
+$ function gnoll() { python3 -m gnoll --breakdown "$@" ; }
+$ gnoll 3d6 + 10
+[5, 5, 4] --> 24
+```
+
 ### 🛠️ Installing From Source
 #### Basic Requirements
 ```bash

src/python/code/gnoll/__init__.py

@@ -48,20 +48,18 @@ def roll(s,
  mock=None,
  mock_const=3,
  breakdown=False,
- builtins=False):
+ builtins=False,
+ keep_temp_file=False):
  """Parse some dice notation with GNOLL.
  @param s the string to parse
  @param verbose whether to enable verbosity (primarily for debug)
  @param mock override the internal random number generator (for testing).
  @param mock_const the seed value for overriding with mocks
  @param breakdown get the details of each dice rolled, not just the final result
+ @param keep_temp_file don't delete the temporary file
  @param force_dll_reload destroy the dll/shared object and reload (inadvisable)
  @return return code, final result, dice breakdown (None if disabled)
  """
- temp = tempfile.NamedTemporaryFile(prefix="gnoll_roll_",
- suffix=".die",
- delete=False)
-
  def make_native_type(v):
  """
  Change a string to a more appropriate type if possible.
@@ -87,36 +85,48 @@ def extract_from_dice_file(lines, seperator):
  v = [list(map(make_native_type, x)) for x in v]
  return v
 
- die_file = temp.name
- os.remove(die_file)
+ try:
+ temp = tempfile.NamedTemporaryFile(prefix="gnoll_roll_",
+ suffix=".die",
+ delete=False)
+ temp.close()
+
+ die_file = temp.name
+
+ out_file = str(die_file).encode("ascii")
+ if verbose:
+ print("Rolling: ", s)
+ print("Output in:", out_file)
+
+ s = s.encode("ascii")
 
- out_file = str(die_file).encode("ascii")
- if verbose:
- print("Rolling: ", s)
- print("Output in:", out_file)
+ return_code = libc.roll_full_options(
+ s,
+ out_file,
+ verbose, # enable_verbose
+ breakdown, # enable_introspect
+ mock is not None, # enable_mock
+ builtins, # enable_builtins
+ mock,
+ mock_const,
+ )
+ if return_code != 0:
+ raise_gnoll_error(return_code)
 
- s = s.encode("ascii")
+ with open(out_file, encoding="utf-8") as f:
+ lines = f.readlines()
 
- return_code = libc.roll_full_options(
- s,
- out_file,
- verbose, # enable_verbose
- breakdown, # enable_introspect
- mock is not None, # enable_mock
- builtins, # enable_builtins
- mock,
- mock_const,
- )
- if return_code != 0:
- raise_gnoll_error(return_code)
+ dice_breakdown = extract_from_dice_file(lines, ",")
+ result = extract_from_dice_file(lines, ";")
 
- with open(out_file, encoding="utf-8") as f:
- lines = f.readlines()
+ return int(return_code), result, dice_breakdown
 
- dice_breakdown = extract_from_dice_file(lines, ",")
- result = extract_from_dice_file(lines, ";")
+ finally:
+ if not keep_temp_file:
+ if verbose:
+ print("Deleting:", out_file)
 
- return int(return_code), result, dice_breakdown
+  os.remove(die_file)
 
 
 if __name__ == "__main__":

src/python/code/gnoll/__main__.py

@@ -0,0 +1,92 @@
+"""Roll some dice with GNOLL."""
+
+import sys
+import argparse
+import gnoll
+
+
+def parse_cmdline_args(args):
+ """Extract values from the commandline
+ @param args - the arguments from the commandline (excluding the python3 call)
+ """
+ p = argparse.ArgumentParser(
+ description=__doc__,
+ usage='python3 -m gnoll [options] EXPR',
+ add_help=False)
+
+ p.add_argument(
+ 'EXPR',
+ nargs='+',
+ help='a dice expression to evaluate'
+ '(multiple arguments will be joined with spaces)'
+ )
+
+ g = p.add_argument_group('main options')
+ g.add_argument(
+ '-h',
+ '--help',
+ action='help',
+ help='show this help message and exit'
+ )
+ g.add_argument(
+ '-b',
+ '--breakdown',
+ action='store_true',
+ help='show a breakdown into individual dice'
+ )
+ g.add_argument(
+ '--no-builtins',
+ action='store_true',
+ help='disable built-in macros'
+ )
+
+ g = p.add_argument_group('debugging options')
+ g.add_argument(
+ '-v',
+ '--verbose',
+ action='store_true',
+ help='enable verbosity'
+ )
+ g.add_argument(
+ '--keep-temp-file',
+ action='store_true',
+ help="don't delete the created temporary file"
+ )
+ g.add_argument(
+ '--mock',
+ metavar='TYPE',
+ type=int,
+ help='mocking type'
+ )
+ g.add_argument(
+ '--mock-const',
+ metavar='N',
+ type=int,
+ default=3,
+ help='mocking constant'
+ )
+
+ a = p.parse_args(args)
+ a.EXPR = ' '.join(a.EXPR)
+ return a
+
+
+def main(EXPR, no_builtins, **kwargs):
+ """
+ The entry point for gnoll when called via `python -m gnoll`
+ @param EXPR - the expression
+ @param no_builtins - a flag to disable builtins
+ @param **kwargs - other key word arguments to be passed to gnoll.roll
+ """
+ _, [[result]], breakdown = gnoll.roll(
+ EXPR,
+ builtins=not no_builtins,
+ **kwargs)
+ if breakdown:
+ print(breakdown[0], '-->', result)
+ else:
+ print(result)
+
+
+if __name__ == '__main__':
+ main(**vars(parse_cmdline_args(sys.argv[1:])))