Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/nbconvert/preprocessors/highlightmagics.py: 43%

1"""This preprocessor detect cells using a different language through 

2magic extensions such as `%%R` or `%%octave`. Cell's metadata is marked 

3so that the appropriate highlighter can be used in the `highlight` 

4filter. 

5""" 

6 

7# Copyright (c) Jupyter Development Team. 

8# Distributed under the terms of the Modified BSD License. 

9 

10import re 

11 

12from traitlets import Dict 

13 

14from .base import Preprocessor 

15 

16 

17class HighlightMagicsPreprocessor(Preprocessor): 

18 """ 

19 Detects and tags code cells that use a different languages than Python. 

20 """ 

21 

22 # list of magic language extensions and their associated pygment lexers 

23 default_languages = Dict( 

24 { 

25 "%%R": "r", 

26 "%%bash": "bash", 

27 "%%cython": "cython", 

28 "%%javascript": "javascript", 

29 "%%julia": "julia", 

30 "%%latex": "latex", 

31 "%%octave": "octave", 

32 "%%perl": "perl", 

33 "%%ruby": "ruby", 

34 "%%sh": "sh", 

35 "%%sql": "sql", 

36 } 

37 ) 

38 

39 # user defined language extensions 

40 languages = Dict( 

41 help=( 

42 "Syntax highlighting for magic's extension languages. " 

43 "Each item associates a language magic extension such as %%R, " 

44 "with a pygments lexer such as r." 

45 ) 

46 ).tag(config=True) 

47 

48 def __init__(self, config=None, **kw): 

49 """Public constructor""" 

50 

51 super().__init__(config=config, **kw) 

52 

53 # Update the default languages dict with the user configured ones 

54 self.default_languages.update(self.languages) 

55 

56 # build a regular expression to catch language extensions and choose 

57 # an adequate pygments lexer 

58 any_language = "|".join(self.default_languages.keys()) 

59 self.re_magic_language = re.compile(rf"^\s*({any_language})\s+") 

60 

61 def which_magic_language(self, source): 

62 """ 

63 When a cell uses another language through a magic extension, 

64 the other language is returned. 

65 If no language magic is detected, this function returns None. 

66 

67 Parameters 

68 ---------- 

69 source: str 

70 Source code of the cell to highlight 

71 """ 

72 

73 m = self.re_magic_language.match(source) 

74 

75 if m: 

76 # By construction of the re, the matched language must be in the 

77 # languages dictionary 

78 return self.default_languages[m.group(1)] 

79 return None 

80 

81 def preprocess_cell(self, cell, resources, cell_index): 

82 """ 

83 Tags cells using a magic extension language 

84 

85 Parameters 

86 ---------- 

87 cell : NotebookNode cell 

88 Notebook cell being processed 

89 resources : dictionary 

90 Additional resources used in the conversion process. Allows 

91 preprocessors to pass variables into the Jinja engine. 

92 cell_index : int 

93 Index of the cell being processed (see base.py) 

94 """ 

95 

96 # Only tag code cells 

97 if cell.cell_type == "code": 

98 magic_language = self.which_magic_language(cell.source) 

99 if magic_language: 

100 cell["metadata"]["magics_language"] = magic_language 

101 return cell, resources