Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/pyparsing/actions.py: 44%

1# actions.py 

2 

3from .exceptions import ParseException 

4from .util import col, replaced_by_pep8 

5 

6 

7class OnlyOnce: 

8 """ 

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

10 """ 

11 

12 def __init__(self, method_call): 

13 from .core import _trim_arity 

14 

15 self.callable = _trim_arity(method_call) 

16 self.called = False 

17 

18 def __call__(self, s, l, t): 

19 if not self.called: 

20 results = self.callable(s, l, t) 

21 self.called = True 

22 return results 

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

24 

25 def reset(self): 

26 """ 

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

28 """ 

29 

30 self.called = False 

31 

32 

33def match_only_at_col(n): 

34 """ 

35 Helper method for defining parse actions that require matching at 

36 a specific column in the input text. 

37 """ 

38 

39 def verify_col(strg, locn, toks): 

40 if col(locn, strg) != n: 

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

42 

43 return verify_col 

44 

45 

46def replace_with(repl_str): 

47 """ 

48 Helper method for common parse actions that simply return 

49 a literal value. Especially useful when used with 

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

51 

52 Example:: 

53 

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

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

56 term = na | num 

57 

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

59 """ 

60 return lambda s, l, t: [repl_str] 

61 

62 

63def remove_quotes(s, l, t): 

64 """ 

65 Helper parse action for removing quotation marks from parsed 

66 quoted strings. 

67 

68 Example:: 

69 

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

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

72 

73 # use remove_quotes to strip quotation marks from parsed results 

74 quoted_string.set_parse_action(remove_quotes) 

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

76 """ 

77 return t[0][1:-1] 

78 

79 

80def with_attribute(*args, **attr_dict): 

81 """ 

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

83 tags created with :class:`make_xml_tags` or 

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

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

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

87 

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

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

90 

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

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

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

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

95 

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

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

98 

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

100 :class:`with_class`. 

101 

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

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

104 

105 Example:: 

106 

107 html = ''' 

108 <div> 

109 Some text 

110 <div type="grid">1 4 0 1 0</div> 

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

112 <div>this has no type</div> 

113 </div> 

114 

115 ''' 

116 div,div_end = make_html_tags("div") 

117 

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

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

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

121 for grid_header in grid_expr.search_string(html): 

122 print(grid_header.body) 

123 

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

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

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

127 for div_header in div_expr.search_string(html): 

128 print(div_header.body) 

129 

130 prints:: 

131 

132 1 4 0 1 0 

133 

134 1 4 0 1 0 

135 1,3 2,3 1,1 

136 """ 

137 if args: 

138 attrs = args[:] 

139 else: 

140 attrs = attr_dict.items() 

141 attrs = [(k, v) for k, v in attrs] 

142 

143 def pa(s, l, tokens): 

144 for attrName, attrValue in attrs: 

145 if attrName not in tokens: 

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

147 if attrValue != with_attribute.ANY_VALUE and tokens[attrName] != attrValue: 

148 raise ParseException( 

149 s, 

150 l, 

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

152 ) 

153 

154 return pa 

155 

156 

157with_attribute.ANY_VALUE = object() # type: ignore [attr-defined] 

158 

159 

160def with_class(classname, namespace=""): 

161 """ 

162 Simplified version of :class:`with_attribute` when 

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

164 a reserved word in Python. 

165 

166 Example:: 

167 

168 html = ''' 

169 <div> 

170 Some text 

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

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

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

174 </div> 

175 

176 ''' 

177 div,div_end = make_html_tags("div") 

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

179 

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

181 for grid_header in grid_expr.search_string(html): 

182 print(grid_header.body) 

183 

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

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

186 for div_header in div_expr.search_string(html): 

187 print(div_header.body) 

188 

189 prints:: 

190 

191 1 4 0 1 0 

192 

193 1 4 0 1 0 

194 1,3 2,3 1,1 

195 """ 

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

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

198 

199 

200# pre-PEP8 compatibility symbols 

201# fmt: off 

202@replaced_by_pep8(replace_with) 

203def replaceWith(): ... 

204 

205@replaced_by_pep8(remove_quotes) 

206def removeQuotes(): ... 

207 

208@replaced_by_pep8(with_attribute) 

209def withAttribute(): ... 

210 

211@replaced_by_pep8(with_class) 

212def withClass(): ... 

213 

214@replaced_by_pep8(match_only_at_col) 

215def matchOnlyAtCol(): ... 

216 

217# fmt: on