Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/graphviz/backend/dot_command.py: 90%

1"""Check and assemble commands for running Graphviz ``dot``.""" 

2 

3import os 

4import pathlib 

5import typing 

6 

7from .. import exceptions 

8from .. import parameters 

9 

10__all__ = ['DOT_BINARY', 'command'] 

11 

12DOT_BINARY = pathlib.Path('dot') 

13 

14 

15def command(engine: str, format_: str, *, 

16 renderer: typing.Optional[str] = None, 

17 formatter: typing.Optional[str] = None, 

18 neato_no_op: typing.Union[bool, int, None] = None 

19 ) -> typing.List[typing.Union[os.PathLike, str]]: 

20 """Return ``subprocess.Popen`` argument list for rendering. 

21 

22 See also: 

23 Upstream documentation: 

24 - https://www.graphviz.org/doc/info/command.html#-K 

25 - https://www.graphviz.org/doc/info/command.html#-T 

26 - https://www.graphviz.org/doc/info/command.html#-n 

27 """ 

28 if formatter is not None and renderer is None: 

29 raise exceptions.RequiredArgumentError('formatter given without renderer') 

30 

31 parameters.verify_engine(engine, required=True) 

32 parameters.verify_format(format_, required=True) 

33 parameters.verify_renderer(renderer, required=False) 

34 parameters.verify_formatter(formatter, required=False) 

35 

36 output_format = [f for f in (format_, renderer, formatter) if f is not None] 

37 output_format_flag = ':'.join(output_format) 

38 

39 cmd = [DOT_BINARY, f'-K{engine}', f'-T{output_format_flag}'] 

40 

41 if neato_no_op: 

42 cmd.append(f'-n{neato_no_op:d}') 

43 

44 return cmd