Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/pyparsing/actions.py: 42%

1# actions.py 

2from __future__ import annotations 

3 

4from typing import Union, Callable, Any 

5 

6from .exceptions import ParseException 

7from .util import col, replaced_by_pep8 

8from .results import ParseResults 

9 

10 

11ParseAction = Union[ 

12 Callable[[], Any], 

13 Callable[[ParseResults], Any], 

14 Callable[[int, ParseResults], Any], 

15 Callable[[str, int, ParseResults], Any], 

16] 

17 

18 

19class OnlyOnce: 

20 """ 

21 Wrapper for parse actions, to ensure they are only called once. 

22 Note: parse action signature must include all 3 arguments. 

23 """ 

24 

25 def __init__(self, method_call: Callable[[str, int, ParseResults], Any]) -> None: 

26 from .core import _trim_arity 

27 

28 self.callable = _trim_arity(method_call) 

29 self.called = False 

30 

31 def __call__(self, s: str, l: int, t: ParseResults) -> ParseResults: 

32 if not self.called: 

33 results = self.callable(s, l, t) 

34 self.called = True 

35 return results 

36 raise ParseException(s, l, "OnlyOnce obj called multiple times w/out reset") 

37 

38 def reset(self): 

39 """ 

40 Allow the associated parse action to be called once more. 

41 """ 

42 

43 self.called = False 

44 

45 

46def match_only_at_col(n: int) -> ParseAction: 

47 """ 

48 Helper method for defining parse actions that require matching at 

49 a specific column in the input text. 

50 """ 

51 

52 def verify_col(strg: str, locn: int, toks: ParseResults) -> None: 

53 if col(locn, strg) != n: 

54 raise ParseException(strg, locn, f"matched token not at column {n}") 

55 

56 return verify_col 

57 

58 

59def replace_with(repl_str: str) -> ParseAction: 

60 """ 

61 Helper method for common parse actions that simply return 

62 a literal value. Especially useful when used with 

63 :class:`transform_string<ParserElement.transform_string>` (). 

64 

65 Example:: 

66 

67 num = Word(nums).set_parse_action(lambda toks: int(toks[0])) 

68 na = one_of("N/A NA").set_parse_action(replace_with(math.nan)) 

69 term = na | num 

70 

71 term[1, ...].parse_string("324 234 N/A 234") # -> [324, 234, nan, 234] 

72 """ 

73 return lambda s, l, t: [repl_str] 

74 

75 

76def remove_quotes(s: str, l: int, t: ParseResults) -> Any: 

77 """ 

78 Helper parse action for removing quotation marks from parsed 

79 quoted strings. 

80 

81 Example:: 

82 

83 # by default, quotation marks are included in parsed results 

84 quoted_string.parse_string("'Now is the Winter of our Discontent'") # -> ["'Now is the Winter of our Discontent'"] 

85 

86 # use remove_quotes to strip quotation marks from parsed results 

87 quoted_string.set_parse_action(remove_quotes) 

88 quoted_string.parse_string("'Now is the Winter of our Discontent'") # -> ["Now is the Winter of our Discontent"] 

89 """ 

90 return t[0][1:-1] 

91 

92 

93def with_attribute(*args: tuple[str, str], **attr_dict) -> ParseAction: 

94 """ 

95 Helper to create a validating parse action to be used with start 

96 tags created with :class:`make_xml_tags` or 

97 :class:`make_html_tags`. Use ``with_attribute`` to qualify 

98 a starting tag with a required attribute value, to avoid false 

99 matches on common tags such as ``<TD>`` or ``<DIV>``. 

100 

101 Call ``with_attribute`` with a series of attribute names and 

102 values. Specify the list of filter attributes names and values as: 

103 

104 - keyword arguments, as in ``(align="right")``, or 

105 - as an explicit dict with ``**`` operator, when an attribute 

106 name is also a Python reserved word, as in ``**{"class":"Customer", "align":"right"}`` 

107 - a list of name-value tuples, as in ``(("ns1:class", "Customer"), ("ns2:align", "right"))`` 

108 

109 For attribute names with a namespace prefix, you must use the second 

110 form. Attribute names are matched insensitive to upper/lower case. 

111 

112 If just testing for ``class`` (with or without a namespace), use 

113 :class:`with_class`. 

114 

115 To verify that the attribute exists, but without specifying a value, 

116 pass ``with_attribute.ANY_VALUE`` as the value. 

117 

118 Example:: 

119 

120 html = ''' 

121 <div> 

122 Some text 

123 <div type="grid">1 4 0 1 0</div> 

124 <div type="graph">1,3 2,3 1,1</div> 

125 <div>this has no type</div> 

126 </div> 

127 ''' 

128 div,div_end = make_html_tags("div") 

129 

130 # only match div tag having a type attribute with value "grid" 

131 div_grid = div().set_parse_action(with_attribute(type="grid")) 

132 grid_expr = div_grid + SkipTo(div | div_end)("body") 

133 for grid_header in grid_expr.search_string(html): 

134 print(grid_header.body) 

135 

136 # construct a match with any div tag having a type attribute, regardless of the value 

137 div_any_type = div().set_parse_action(with_attribute(type=with_attribute.ANY_VALUE)) 

138 div_expr = div_any_type + SkipTo(div | div_end)("body") 

139 for div_header in div_expr.search_string(html): 

140 print(div_header.body) 

141 

142 prints:: 

143 

144 1 4 0 1 0 

145 

146 1 4 0 1 0 

147 1,3 2,3 1,1 

148 """ 

149 attrs_list: list[tuple[str, str]] = [] 

150 if args: 

151 attrs_list.extend(args) 

152 else: 

153 attrs_list.extend(attr_dict.items()) 

154 

155 def pa(s: str, l: int, tokens: ParseResults) -> None: 

156 for attrName, attrValue in attrs_list: 

157 if attrName not in tokens: 

158 raise ParseException(s, l, "no matching attribute " + attrName) 

159 if attrValue != with_attribute.ANY_VALUE and tokens[attrName] != attrValue: # type: ignore [attr-defined] 

160 raise ParseException( 

161 s, 

162 l, 

163 f"attribute {attrName!r} has value {tokens[attrName]!r}, must be {attrValue!r}", 

164 ) 

165 

166 return pa 

167 

168 

169with_attribute.ANY_VALUE = object() # type: ignore [attr-defined] 

170 

171 

172def with_class(classname: str, namespace: str = "") -> ParseAction: 

173 """ 

174 Simplified version of :class:`with_attribute` when 

175 matching on a div class - made difficult because ``class`` is 

176 a reserved word in Python. 

177 

178 Example:: 

179 

180 html = ''' 

181 <div> 

182 Some text 

183 <div class="grid">1 4 0 1 0</div> 

184 <div class="graph">1,3 2,3 1,1</div> 

185 <div>this &lt;div&gt; has no class</div> 

186 </div> 

187 

188 ''' 

189 div,div_end = make_html_tags("div") 

190 div_grid = div().set_parse_action(with_class("grid")) 

191 

192 grid_expr = div_grid + SkipTo(div | div_end)("body") 

193 for grid_header in grid_expr.search_string(html): 

194 print(grid_header.body) 

195 

196 div_any_type = div().set_parse_action(with_class(withAttribute.ANY_VALUE)) 

197 div_expr = div_any_type + SkipTo(div | div_end)("body") 

198 for div_header in div_expr.search_string(html): 

199 print(div_header.body) 

200 

201 prints:: 

202 

203 1 4 0 1 0 

204 

205 1 4 0 1 0 

206 1,3 2,3 1,1 

207 """ 

208 classattr = f"{namespace}:class" if namespace else "class" 

209 return with_attribute(**{classattr: classname}) 

210 

211 

212# Compatibility synonyms 

213# fmt: off 

214replaceWith = replaced_by_pep8("replaceWith", replace_with) 

215removeQuotes = replaced_by_pep8("removeQuotes", remove_quotes) 

216withAttribute = replaced_by_pep8("withAttribute", with_attribute) 

217withClass = replaced_by_pep8("withClass", with_class) 

218matchOnlyAtCol = replaced_by_pep8("matchOnlyAtCol", match_only_at_col) 

219# fmt: on