Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/nbconvert/preprocessors/csshtmlheader.py: 42%

1"""Module that pre-processes the notebook for export to HTML. 

2""" 

3 

4# Copyright (c) Jupyter Development Team. 

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

6 

7import hashlib 

8import os 

9 

10from jupyterlab_pygments import JupyterStyle # type:ignore 

11from pygments.style import Style 

12from traitlets import Type, Unicode, Union 

13 

14from .base import Preprocessor 

15 

16try: 

17 from notebook import DEFAULT_STATIC_FILES_PATH # type:ignore 

18except ImportError: 

19 DEFAULT_STATIC_FILES_PATH = None 

20 

21 

22class CSSHTMLHeaderPreprocessor(Preprocessor): 

23 """ 

24 Preprocessor used to pre-process notebook for HTML output. Adds IPython notebook 

25 front-end CSS and Pygments CSS to HTML output. 

26 """ 

27 

28 highlight_class = Unicode(".highlight", help="CSS highlight class identifier").tag(config=True) 

29 

30 style = Union( 

31 [Unicode("default"), Type(klass=Style)], 

32 help="Name of the pygments style to use", 

33 default_value=JupyterStyle, 

34 ).tag(config=True) 

35 

36 def __init__(self, *pargs, **kwargs): 

37 """Initialize the preprocessor.""" 

38 Preprocessor.__init__(self, *pargs, **kwargs) 

39 self._default_css_hash = None 

40 

41 def preprocess(self, nb, resources): 

42 """Fetch and add CSS to the resource dictionary 

43 

44 Fetch CSS from IPython and Pygments to add at the beginning 

45 of the html files. Add this css in resources in the 

46 "inlining.css" key 

47 

48 Parameters 

49 ---------- 

50 nb : NotebookNode 

51 Notebook being converted 

52 resources : dictionary 

53 Additional resources used in the conversion process. Allows 

54 preprocessors to pass variables into the Jinja engine. 

55 """ 

56 resources["inlining"] = {} 

57 resources["inlining"]["css"] = self._generate_header(resources) 

58 return nb, resources 

59 

60 def _generate_header(self, resources): 

61 """ 

62 Fills self.header with lines of CSS extracted from IPython 

63 and Pygments. 

64 """ 

65 from pygments.formatters import HtmlFormatter 

66 

67 header = [] 

68 

69 formatter = HtmlFormatter(style=self.style) 

70 pygments_css = formatter.get_style_defs(self.highlight_class) 

71 header.append(pygments_css) 

72 

73 # Load the user's custom CSS and IPython's default custom CSS. If they 

74 # differ, assume the user has made modifications to his/her custom CSS 

75 # and that we should inline it in the nbconvert output. 

76 config_dir = resources["config_dir"] 

77 custom_css_filename = os.path.join(config_dir, "custom", "custom.css") 

78 if os.path.isfile(custom_css_filename): 

79 if DEFAULT_STATIC_FILES_PATH and self._default_css_hash is None: 

80 self._default_css_hash = self._hash( 

81 os.path.join(DEFAULT_STATIC_FILES_PATH, "custom", "custom.css") 

82 ) 

83 if self._hash(custom_css_filename) != self._default_css_hash: 

84 with open(custom_css_filename, encoding="utf-8") as f: 

85 header.append(f.read()) 

86 return header 

87 

88 def _hash(self, filename): 

89 """Compute the hash of a file.""" 

90 md5 = hashlib.md5() # noqa 

91 with open(filename, "rb") as f: 

92 md5.update(f.read()) 

93 return md5.digest()