Parse svg: ścieżka d atrybut

Question

Potrzebuję odszyfrować element ścieżki w dokumencie SVG, aby sterować maszyną CNC wzdłuż tej ścieżki. Zastanawiam się, czy są jakieś biblioteki Python że analizowania SVG i dać jakąś pythonic listy atrybutu d, np:

<path d="M 20 30 L 20 20 20 40 40 40"/> 

analizuje się

[["M", 20, 30], 
["L", 20, 20], 
["L", 20, 40], 
["L", 40, 40]] 

Answer 1

Oto początek jest napisane przeze mnie, aw python 2.7.2. Po prostu usuń testy i wydrukuj wyciągi, jeśli chcesz.

Copyright 2012 Christopher L. Ramsey 

    Licensed under the Apache License, Version 2.0 (the "License"); 
    you may not use this file except in compliance with the License. 
    You may obtain a copy of the License at 

     http://www.apache.org/licenses/LICENSE-2.0 

    Unless required by applicable law or agreed to in writing, software 
    distributed under the License is distributed on an "AS IS" BASIS, 
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
    See the License for the specific language governing permissions and 
    limitations under the License. 

from collections import OrderedDict 
from re import match 
from re import split 
from re import sub 

class PathIterator(object): 
    EOI = 'End of Iteration' 
    PATH_IDENTIFIERS = r'[MLHVCSQTAmlhvcsqa]' 
    NUMBERS = r'[0-9.-^A-z]' 
    SEPERATORS = r'\s|\,' 
    PATH_END = r'[Zz]' 

    def __init__(self, path): 
     self.parseable = path.translate(None, '\t\f') 
     self.parseable = self.parseable.replace('\n', ' ') 
     print 'strip_newlines: {}'.format(self.parseable) 
     self.parseable = sub(r'([A-Za-z])([0-9]|\-)', self.insert, self.parseable) 
     print 'add_space: {}'.format(self.parseable) 
     self.parseable = self.parseable.replace(',', ' ') 
     print 'replace_commas: {}'.format(self.parseable) 
     self.parseable = sub(r'\s+', ' ', self.parseable) # replace any double space with a single space 
     print 'strip_extra_space: {}'.format(self.parseable) 
     self.tokens = split(' ', self.parseable) 
     self.map = self.produce_map(self.tokens) 
     print self.map 
     self.elements = self.process(self.map) 

    def produce_map(self, tkns): 
     self.m = OrderedDict() 
     self.i = 0 
     while self.i < len(tkns): 
      if match(self.PATH_IDENTIFIERS, tkns[self.i]): 
       self.m[self.i] = tkns[self.i] 
      elif match(self.PATH_END, tkns[self.i]): 
       self.m[self.i] = tkns[self.i] 
      else: 
       pass 
      self.i += 1 
     return self.m.items() 

    def process(self, map): 
     self.mm = [] 
     self.l = len(map) 
     for e in range(self.l): 
      try: 
       self.element = map[e] 
       self.future = map[e + 1] 
       self.ident = self.element[1] 
       self.start = self.element[0] + 1 
       self.end = self.future[0] 
       self.nbrs = self.tokens[self.start:self.end] 
      except: 
       self.element = map[e] 
       self.ident = self.element[1] 
       self.start = self.element[0] + 1 
       self.end = len(self.tokens) 
       self.nbrs = self.tokens[self.start:self.end] 
       print 'start: {} end {}'.format(self.start, self.end) 
      finally: 
       self.numbers = [] 
       for number in self.nbrs: 
        self.numbers.append(float(number)) 
       self.mm.append((self.ident, self.numbers)) 
     return iter(self.mm) 

    def next(self): 
     try: 
      return self.elements.next() 
     except: 
      return self.EOI 

    def insert(self, match_obj): 
     self.group = match_obj.group() 
     return '{} {}'.format(self.group[0], self.group[1]) 

if __name__ == '__main__': 
    inkscape_path = "M 12,90 C 8.676,90 6,87.324 6,84 L 6,82 6,14 6,12 c 0,-0.334721 0.04135,-0.6507 0.09375,-0.96875 0.0487,-0.295596 0.09704,-0.596915 0.1875,-0.875 C 6.29113,10.12587 6.302142,10.09265 6.3125,10.0625 6.411365,9.774729 6.5473802,9.515048 6.6875,9.25 6.8320918,8.976493 7.0031161,8.714385 7.1875,8.46875 7.3718839,8.223115 7.5612765,7.995278 7.78125,7.78125 8.221197,7.353194 8.72416,6.966724 9.28125,6.6875 9.559795,6.547888 9.8547231,6.440553 10.15625,6.34375 9.9000482,6.443972 9.6695391,6.580022 9.4375,6.71875 c -0.00741,0.0044 -0.023866,-0.0045 -0.03125,0 -0.031933,0.0193 -0.062293,0.04251 -0.09375,0.0625 -0.120395,0.0767 -0.2310226,0.163513 -0.34375,0.25 -0.1061728,0.0808 -0.2132809,0.161112 -0.3125,0.25 C 8.4783201,7.442683 8.3087904,7.626638 8.15625,7.8125 8.0486711,7.942755 7.9378561,8.077785 7.84375,8.21875 7.818661,8.25713 7.805304,8.30462 7.78125,8.34375 7.716487,8.446782 7.6510225,8.548267 7.59375,8.65625 7.4927417,8.850956 7.3880752,9.071951 7.3125,9.28125 7.30454,9.30306 7.288911,9.3218 7.28125,9.34375 7.2494249,9.4357 7.2454455,9.530581 7.21875,9.625 7.1884177,9.731618 7.1483606,9.828031 7.125,9.9375 7.0521214,10.279012 7,10.635705 7,11 l 0,2 0,68 0,2 c 0,2.781848 2.2181517,5 5,5 l 2,0 68,0 2,0 c 2.781848,0 5,-2.218152 5,-5 l 0,-2 0,-68 0,-2 C 89,10.635705 88.94788,10.279012 88.875,9.9375 88.83085,9.730607 88.78662,9.539842 88.71875,9.34375 88.71105,9.3218 88.69545,9.30306 88.6875,9.28125 88.62476,9.107511 88.549117,8.913801 88.46875,8.75 88.42717,8.6672 88.38971,8.580046 88.34375,8.5 88.28915,8.40279 88.216976,8.31165 88.15625,8.21875 88.06214,8.077785 87.951329,7.942755 87.84375,7.8125 87.700576,7.63805 87.540609,7.465502 87.375,7.3125 87.36383,7.3023 87.35502,7.29135 87.34375,7.28125 87.205364,7.155694 87.058659,7.046814 86.90625,6.9375 86.803679,6.86435 86.701932,6.784136 86.59375,6.71875 c -0.0074,-0.0045 -0.02384,0.0044 -0.03125,0 -0.232039,-0.138728 -0.462548,-0.274778 -0.71875,-0.375 0.301527,0.0968 0.596455,0.204138 0.875,0.34375 0.55709,0.279224 1.060053,0.665694 1.5,1.09375 0.219973,0.214028 0.409366,0.441865 0.59375,0.6875 0.184384,0.245635 0.355408,0.507743 0.5,0.78125 0.14012,0.265048 0.276135,0.524729 0.375,0.8125 0.01041,0.03078 0.02133,0.06274 0.03125,0.09375 0.09046,0.278085 0.1388,0.579404 0.1875,0.875 C 89.95865,11.3493 90,11.665279 90,12 l 0,2 0,68 0,2 c 0,3.324 -2.676,6 -6,6 l -72,0 z" 
    mdn_path = "M10 80 Q 52.5 10, 95 80 T 180 80" 
    w3c_path = "M100,200 C100,100 250,100 250,200 S400,300 400,200" 
    w3c_path_neg = "M-100,200 C100,100 250,100 250,200 S-400,300 400,200" 
    w3c_path_nl = ''' 
      M600,350 l 50,-25 
      a25,25 -30 0,1 50,-25 l 50,-25 
      a25,50 -30 0,1 50,-25 l 50,-25 
      a25,75 -30 0,1 50,-25 l 50,-25 
      a25,100 -30 0,1 50,-25 l 50,-25 
      ''' 
    paths = [inkscape_path, mdn_path, w3c_path, str.strip(w3c_path_nl), w3c_path_neg] 
    for path in paths: 
     p = PathIterator(path) 
     char = '' 
     while char != PathIterator.EOI: 
      char = p.next() 
      print char 

Answer 2

Pierwsze d-ciąg może być w paru liniach wykorzystujących svgpathtools, reszta może być wykonane przy użyciu wyrażeń regularnych.

from svgpathtools import svg2paths 
paths, attributes = svg2paths('some_svg_file.svg') 

ścieżki znajduje się lista obiektów svgpathtools ścieżki (zawierających tylko informacje krzywa, nie kolory, style, itp.) atrybuty to lista obiektów słownikowych atrybutów.

Załóżmy, że ścieżka jesteś zainteresowany jest pierwszy (the 0-ci) wymienione w SVG, a następnie wyodrębnić tylko d-ciąg można użyć:

d = attributes[0]['d'] # d-string from first path in SVG 

# Now for some regular expressions magic 
import re 
split_by_letters = re.findall('[A-Z|a-z][^A-Z|a-z]*', d) 
split_as_you_want = [] 
for x in split_by_letters: 
    nums = x[1:].replace(',',' ').split() # list of numbers after letter 
    for k in range(len(nums) // 2): 
     split_as_you_want.append([x[0]] + [nums[k]] + [nums[k+1]]) 
print split_as_you_want 

Nie przekonwertować Numery w łańcuchy tutaj, jak chcesz to zrobić, zależy od tego, czy są one zawsze liczbami całkowitymi i czy zależy ci na tym. W większości przypadków można to zrobić za pomocą czegoś takiego jak poniżej linii "nums = ...".

for k, n in enumerate(nums): 
    try: 
     nums[k] = int(n) 
    except ValueError: 
     nums[k] = float(n)