문제
I have a number of MULTIPOLYGONS in the form of WKT (Well Known Text) like this:
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)))
I need a program to determine these types for me given the geometry. I tried to use regular expression in python. Since the only difference between the geometries are parenthesis, I tried to use them as patterns, but it does not work. My attempt to identify A single multipolygon with one hole was something like this:
https://stackoverflow.com/questions/21210086
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Russianstr1=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
Why it cannot use parenthesis as patterns and what could be a possible solution?
해결책 2
You can use this pattern:
MULTIPOLYGON\(\(\(-?\d+ -?\d+(?:, -?\d+ -?\d+)*\),\(-?\d+ -?\d+(?:, -?\d+ -?\d+)*\)\)\)
Description of pattern elements:
\( # literal parenthesis (must be escaped)
(?:..) # non capturing group (useful to repeat the same pattern with * or +)
\d # a digit
-? # optional -
다른 팁
Would you consider going with a parser rather than a regex? (A parser could create actual MultiPolygon and Polygon objects, and these can have fields for whatever you need to fish out from the text.) For example, something like this:
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)
`
Running this program your example text, the output is:
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
This might help you, but its tested in Perl.
edit you need a regex processing tool to manage this kind of work.
I used RegexFormat4 It took your parenthesised strings and formatted to get indentation. It then escaped the literals. I cut'n pasted the parts together, compressed each individually, then compressed the whole thing. Tested in Perl, took about 10 minutes.
You can add any other combination you need, but I recommend that tool to work on this kind of thing.
Good Luck!
# (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 test case
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)))
Output >>
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)))'
----------
