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我有许多 WKT（众所周知的文本）形式的 MULTIPOLYGONS，如下所示：

没有孔的单个多面体：
多面体(((11 -17, -8 -1, 14 -8, 18 -17, 3 -11, 0 18, -17 -12, -17 -10, -10 -13)))

有一个孔的单个多面体：
多面体(((14 7, -12 18, -13 -12, -7 19, 0 -16, 11 16, 19 18),(5 -11, -12 1, 0 -4, 1 -1)))

几个没有孔的多面体：
多面体(((14 11, -14 -16, 16 18, 6 -8, -14 6, -20 -5, 12 -1, 2 -19, -15 10, 7 2)),((-16 - 15, -16 -15, 19 -2, -2 -13, 3 -19, -16 14, -1 -20)),((0 2, -18 8, -20 17, 12 5, 13 17, -9 -8, -20 -8, 20 -6, -12 0, -9 -4, -5 -14, -16 -19)),((-15 -16, -14 2, 19 -18, 4 8, 18 -1, -2 -13)),((-10 9, -12 15, -16 20, -15 -13, -17 16, -11 3, 18 -13, -3 13, - 6 1, 2 12)))

多个多边形，其中至少一个有孔：
多多边形(((-8 0, 10 -7, 15 0, 0 14, -11 -13, -15 -5),(-6 -19, -18 -8, -9 -18, -1 2, 10 -8, -1 -12, -9 -16)),((0 19, -8 -10, -12 -12, 15 -20, 9 9, 16 5),(8 4, 8 0, 2 7 , -17 8, 13 17, -6 -7)),((-9 -1, 19 9, -15 -11, -4 -14, -3 18),(-4 -15, 7 8, 5 -6, 20 13, 0 7, -10 -18)),((19 0, -13 1, -10 -12, -8 7, -1 14, 17 11),(0 -10, -1 - 20, -14 7)),((-20 -7, 3 -7, 15 2, -7 -7),(9 -18, 13 -2, -15 -8, -2 -9)),( (-18 8, 4 15, -1 -12, -13 18, 8 -17, -14 -19, -7 -13, 1 2, -11 -15, 5 20, 12 -14, 4 -10, -17 8, -6 15, -18 15)),((15 -2, 14 2, 17 -2, 6 3, -16 2),(7 0, 17 10, 17 -17, 13 -3, 1 -8)))

给定几何形状，我需要一个程序来为我确定这些类型。我尝试在 python 中使用正则表达式。由于几何之间的唯一区别是括号，因此我尝试将它们用作模式，但它不起作用。我尝试识别带有一个孔的单个多面体是这样的：

str1=poly_single_no_hole
regex=r'),('
p = re.compile(regex, re.IGNORECASE)
m1 = p.match(str1)
print 'str 1 (' + str1 + ') contains is a single multipolygon with no hole:', m1 is not None

为什么它不能使用括号作为模式，什么是可能的解决方案？

4

3 回答 3

2

您会考虑使用解析器而不是正则表达式吗？（解析器可以创建实际的 MultiPolygon 和 Polygon 对象，这些对象可以包含您需要从文本中提取的任何字段。）例如，如下所示：

class Multi_Polygon:
  def __init__(self):
    self.polygons = []

class Polygon:
  def __init__(self):
    self.num_loops = 0

class Token:
  def __init__(self, ch, line, column):
    self.ch = ch
    self.line = line
    self.column = column

class Parser:
  def __init__(self, text):
    self.tokens = []
    line = 1
    column = 0
    for ch in text:
      column += 1
      if ch in {'(', ')', ','}:
        self.tokens.append(Token(ch, line, column))
      elif ch == '\n':
        line += 1
        column = 1
    self.multi_polygons = []
    self.token_index = 0
    self.multi = None
    self.polygon = None
    self.parse()

  def eat(self, ch):
    token = self.tokens[self.token_index]
    if ch != token.ch:
      message = "line %d, column %d, expected '%s', but found '%s'" % (token.line, token.column, ch, token.ch)
      raise Exception(message)
    self.token_index += 1

  def left_paren(self):
    self.eat('(')

  def right_paren(self):
    self.eat(')')

  def ate_comma(self):
    ch = self.tokens[self.token_index].ch
    if (ch != ','):
      return False
    self.token_index += 1
    return True

  def parse(self):
    while self.token_index < len(self.tokens):
      self.parse_multi_polygon()

  def parse_multi_polygon(self):
    self.multi = Multi_Polygon()
    self.left_paren()
    while True:
      self.parse_polygon()
      if not self.ate_comma():
        break
    self.right_paren()
    self.multi_polygons.append(self.multi)
    self.multi = None

  def parse_polygon(self):
    self.polygon = Polygon()
    self.left_paren()
    while True:
      self.parse_loop()
      if not self.ate_comma():
        break
    self.right_paren()
    self.multi.polygons.append(self.polygon)
    self.polygon = None

  def parse_loop(self):
    self.left_paren()
    num_points = 0
    while self.ate_comma():
      num_points += 1
    self.right_paren()
    self.polygon.num_loops += 1

parser = Parser(input_text)
for index, multi_polygon in enumerate(parser.multi_polygons):
  print "multi_polygon %d has %d polygons" % (index, len (multi_polygon.polygons))
  for i, p in enumerate(multi_polygon.polygons):
    print "  polygon %d has %d loops" % (i, p.num_loops)
  `

运行这个程序你的示例文本，输出是：

multi_polygon 0 has 1 polygons
  polygon 0 has 1 loops
multi_polygon 1 has 1 polygons
  polygon 0 has 2 loops
multi_polygon 2 has 5 polygons
  polygon 0 has 1 loops
  polygon 1 has 1 loops
  polygon 2 has 1 loops
  polygon 3 has 1 loops
  polygon 4 has 1 loops
multi_polygon 3 has 7 polygons
  polygon 0 has 2 loops
  polygon 1 has 2 loops
  polygon 2 has 2 loops
  polygon 3 has 2 loops
  polygon 4 has 2 loops
  polygon 5 has 1 loops
  polygon 6 has 2 loops
于 2014-01-19T03:07:23.843 回答
1

您可以使用此模式：

MULTIPOLYGON\(\(\(-?\d+ -?\d+(?:, -?\d+ -?\d+)*\),\(-?\d+ -?\d+(?:, -?\d+ -?\d+)*\)\)\)

图案元素说明：

\(       # literal parenthesis (must be escaped)
(?:..)   # non capturing group (useful to repeat the same pattern with * or +)
\d       # a digit
-?       # optional -
于 2014-01-18T21:43:13.617 回答
1

这可能会对您有所帮助，但它在 Perl 中进行了测试。

编辑您需要一个正则表达式处理工具来管理此类工作。
我使用了RegexFormat4它采用了带括号的字符串并格式化以获得缩进。然后它逃脱了文字。我将零件剪切并粘贴在一起，分别压缩，然后压缩整个东西。在 Perl 中测试，大约需要 10 分钟。
您可以添加您需要的任何其他组合，但我建议使用该工具来处理此类事情。

祝你好运！

 #  (MULTIPOLYGON\(\(\([^)]+\)\)\))|(MULTIPOLYGON\(\(\([^)]+\)(?:,\([^)]+\))+\)\))|(MULTIPOLYGON\(\(\([^)]+\)\)(?:,\(\([^)]+\)\))+\))|(MULTIPOLYGON\((?:(?:(?:(?<=\)),|)\(\([^)]+\)\))*(?:(?:(?<=\)),|)\(\([^)]+\)(?:,\([^)]+\))+\))+(?:(?:(?<=\)),|)\(\([^)]+\)\))*)+\))


    (  # (1)
         # A single multipolygon with no holes:
         #  MULTIPOLYGON\(\(\([^)]+\)\)\)
         MULTIPOLYGON
         \(
         \(
         \( [^)]+ \)
         \)
         \)
    )
 |  
    (  # (2)
         # A single multipolygon with one (or more) hole:
         #  MULTIPOLYGON\(\(\([^)]+\)(?:,\([^)]+\))+\)\)
         MULTIPOLYGON
         \(
         \(
         \( [^)]+  \)
         (?: , \( [^)]+  \) )+
         \)
         \)
    )
 |  
    (  # (3)
         # Several multipolygons with no holes:
         #  MULTIPOLYGON\(\(\([^)]+\)\)(?:,\(\([^)]+\)\))+\)
         MULTIPOLYGON
         \(
         \(
         \(  [^)]+  \)
         \)
         (?:
              ,
              \(
              \( [^)]+ \)
              \)
         )+
         \)
    )
 |  
    (  # (4)
         # Several multipolygons where at least one has a hole:
         #   MULTIPOLYGON\((?:(?:(?:(?<=\)),|)\(\([^)]+\)\))*(?:(?:(?<=\)),|)\(\([^)]+\)(?:,\([^)]+\))+\))+(?:(?:(?<=\)),|)\(\([^)]+\)\))*)+\)
         MULTIPOLYGON
         \(
         (?:
              (?:
                   (?:
                        (?<= \) )
                        ,
                     |  
                   )
                   \(
                   \(  [^)]+  \)
                   \)
              )*
              (?:
                   (?:
                        (?<= \) )
                        ,
                     |  
                   )
                   \(
                   \( [^)]+  \)
                   (?: , \( [^)]+  \) )+
                   \)
              )+
              (?:
                   (?:
                        (?<= \) )
                        ,
                     |  
                   )
                   \(
                   \( [^)]+ \)
                   \)
              )*
         )+
         \)
    )

Perl 测试用例 

 my $str = <DATA>;

 while ( $str =~ /(MULTIPOLYGON\(\(\([^)]+\)\)\))|(MULTIPOLYGON\(\(\([^)]+\)(?:,\([^)]+\))+\)\))|(MULTIPOLYGON\(\(\([^)]+\)\)(?:,\(\([^)]+\)\))+\))|(MULTIPOLYGON\((?:(?:(?:(?<=\)),|)\(\([^)]+\)\))*(?:(?:(?<=\)),|)\(\([^)]+\)(?:,\([^)]+\))+\))+(?:(?:(?<=\)),|)\(\([^)]+\)\))*)+\))/g )
 {

    if ( defined $1 )
         { print "1 - '$1'\n----------\n";  }
    if ( defined $2 )
         { print "2 - '$2'\n----------\n";  }
    if ( defined $3 )
         { print "3 - '$3'\n----------\n";  }
    if ( defined $4 )
         { print "4 - '$4'\n----------\n";  }
 }

 __DATA__

 A single multipolygon with no holes:
 MULTIPOLYGON(((11 -17, -8 -1, 14 -8, 18 -17, 3 -11, 0 18, -17 -12, -17 -10, -10 -13)))

 A single multipolygon with one hole:
 MULTIPOLYGON(((14 7, -12 18, -13 -12, -7 19, 0 -16, 11 16, 19 18),(5 -11, -12 1, 0 -4, 1 -1)))

 Several multipolygons with no holes:
 MULTIPOLYGON(((14 11, -14 -16, 16 18, 6 -8, -14 6, -20 -5, 12 -1, 2 -19, -15 10, 7 2)),((-16 -15, -16 -15, 19 -2, -2 -13, 3 -19, -16 14, -1 -20)),((0 2, -18 8, -20 17, 12 5, 13 17, -9 -8, -20 -8, 20 -6, -12 0, -9 -4, -5 -14, -16 -19)),((-15 -16, -14 2, 19 -18, 4 8, 18 -1, -2 -13)),((-10 9, -12 15, -16 20, -15 -13, -17 16, -11 3, 18 -13, -3 13, -6 1, 2 12)))

 Several multipolygons where at least one has a hole:
 MULTIPOLYGON(((-8 0, 10 -7, 15 0, 0 14, -11 -13, -15 -5),(-6 -19, -18 -8, -9 -18, -1 2, 10 -8, -1 -12, -9 -16)),((0 19, -8 -10, -12 -12, 15 -20, 9 9, 16 5),(8 4, 8 0, 2 7, -17 8, 13 17, -6 -7)),((-9 -1, 19 9, -15 -11, -4 -14, -3 18),(-4 -15, 7 8, 5 -6, 20 13, 0 7, -10 -18)),((19 0, -13 1, -10 -12, -8 7, -1 14, 17 11),(0 -10, -1 -20, -14 7)),((-20 -7, 3 -7, 15 2, -7 -7),(9 -18, 13 -2, -15 -8, -2 -9)),((-18 8, 4 15, -1 -12, -13 18, 8 -17, -14 -19, -7 -13, 1 2, -11 -15, 5 20, 12 -14, 4 -10, -17 8, -6 15, -18 15)),((15 -2, 14 2, 17 -2, 6 3, -16 2),(7 0, 17 10, 17 -17, 13 -3, 1 -8)))

输出>> 

 1 - 'MULTIPOLYGON(((11 -17, -8 -1, 14 -8, 18 -17, 3 -11, 0 18, -17 -12, -17 -10,
  -10 -13)))'
 ----------
 2 - 'MULTIPOLYGON(((14 7, -12 18, -13 -12, -7 19, 0 -16, 11 16, 19 18),(5 -11, -
 12 1, 0 -4, 1 -1)))'
 ----------
 3 - 'MULTIPOLYGON(((14 11, -14 -16, 16 18, 6 -8, -14 6, -20 -5, 12 -1, 2 -19, -1
 5 10, 7 2)),((-16 -15, -16 -15, 19 -2, -2 -13, 3 -19, -16 14, -1 -20)),((0 2, -1
 8 8, -20 17, 12 5, 13 17, -9 -8, -20 -8, 20 -6, -12 0, -9 -4, -5 -14, -16 -19)),
 ((-15 -16, -14 2, 19 -18, 4 8, 18 -1, -2 -13)),((-10 9, -12 15, -16 20, -15 -13,
  -17 16, -11 3, 18 -13, -3 13, -6 1, 2 12)))'
 ----------
 4 - 'MULTIPOLYGON(((-8 0, 10 -7, 15 0, 0 14, -11 -13, -15 -5),(-6 -19, -18 -8, -
 9 -18, -1 2, 10 -8, -1 -12, -9 -16)),((0 19, -8 -10, -12 -12, 15 -20, 9 9, 16 5)
 ,(8 4, 8 0, 2 7, -17 8, 13 17, -6 -7)),((-9 -1, 19 9, -15 -11, -4 -14, -3 18),(-
 4 -15, 7 8, 5 -6, 20 13, 0 7, -10 -18)),((19 0, -13 1, -10 -12, -8 7, -1 14, 17
 11),(0 -10, -1 -20, -14 7)),((-20 -7, 3 -7, 15 2, -7 -7),(9 -18, 13 -2, -15 -8,
 -2 -9)),((-18 8, 4 15, -1 -12, -13 18, 8 -17, -14 -19, -7 -13, 1 2, -11 -15, 5 2
 0, 12 -14, 4 -10, -17 8, -6 15, -18 15)),((15 -2, 14 2, 17 -2, 6 3, -16 2),(7 0,
  17 10, 17 -17, 13 -3, 1 -8)))'
 ----------
于 2014-01-18T22:58:46.783 回答