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: Any) -> 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, that use a single character for quoting. For parsing 

80 strings that may have multiple characters, use the QuotedString class. 

81 

82 Example:: 

83 

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

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

86 

87 # use remove_quotes to strip quotation marks from parsed results 

88 quoted_string.set_parse_action(remove_quotes) 

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

90 """ 

91 return t[0][1:-1] 

92 

93 

94def with_attribute(*args: tuple[str, str], **attr_dict) -> ParseAction: 

95 """ 

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

97 tags created with :class:`make_xml_tags` or 

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

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

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

101 

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

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

104 

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

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

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

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

109 

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

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

112 

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

114 :class:`with_class`. 

115 

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

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

118 

119 Example:: 

120 

121 html = ''' 

122 <div> 

123 Some text 

124 <div type="grid">1 4 0 1 0</div> 

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

126 <div>this has no type</div> 

127 </div> 

128 ''' 

129 div,div_end = make_html_tags("div") 

130 

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

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

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

134 for grid_header in grid_expr.search_string(html): 

135 print(grid_header.body) 

136 

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

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

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

140 for div_header in div_expr.search_string(html): 

141 print(div_header.body) 

142 

143 prints:: 

144 

145 1 4 0 1 0 

146 

147 1 4 0 1 0 

148 1,3 2,3 1,1 

149 """ 

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

151 if args: 

152 attrs_list.extend(args) 

153 else: 

154 attrs_list.extend(attr_dict.items()) 

155 

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

157 for attrName, attrValue in attrs_list: 

158 if attrName not in tokens: 

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

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

161 raise ParseException( 

162 s, 

163 l, 

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

165 ) 

166 

167 return pa 

168 

169 

170with_attribute.ANY_VALUE = object() # type: ignore [attr-defined] 

171 

172 

173def with_class(classname: str, namespace: str = "") -> ParseAction: 

174 """ 

175 Simplified version of :class:`with_attribute` when 

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

177 a reserved word in Python. 

178 

179 Example:: 

180 

181 html = ''' 

182 <div> 

183 Some text 

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

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

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

187 </div> 

188 

189 ''' 

190 div,div_end = make_html_tags("div") 

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

192 

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

194 for grid_header in grid_expr.search_string(html): 

195 print(grid_header.body) 

196 

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

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

199 for div_header in div_expr.search_string(html): 

200 print(div_header.body) 

201 

202 prints:: 

203 

204 1 4 0 1 0 

205 

206 1 4 0 1 0 

207 1,3 2,3 1,1 

208 """ 

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

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

211 

212 

213# Compatibility synonyms 

214# fmt: off 

215replaceWith = replaced_by_pep8("replaceWith", replace_with) 

216removeQuotes = replaced_by_pep8("removeQuotes", remove_quotes) 

217withAttribute = replaced_by_pep8("withAttribute", with_attribute) 

218withClass = replaced_by_pep8("withClass", with_class) 

219matchOnlyAtCol = replaced_by_pep8("matchOnlyAtCol", match_only_at_col) 

220# fmt: on