Python加载带有注释的Json文件实例

# encoding: utf-8
import json
import re
import sys
reload(sys)
sys.setdefaultencoding('utf8')
CAUTION_PRINT_HEAD = 'caution: '
# 创建一个xstr类，用于处理从文件中读出的字符串
class xstr:
 def __init__(self, instr):
  self.instr = instr
 # 删除“//”标志后的注释
 def rmCmt(self): 
  qtCnt = cmtPos = slashPos = 0
  rearLine = self.instr
  # rearline: 前一个“//”之后的字符串，
  # 双引号里的“//”不是注释标志，所以遇到这种情况，仍需继续查找后续的“//”
  while rearLine.find('//') >= 0: # 查找“//”
   slashPos = rearLine.find('//')
   cmtPos += slashPos
   # print 'slashPos: ' + str(slashPos)
   headLine = rearLine[:slashPos]
   while headLine.find('"') >= 0: # 查找“//”前的双引号
    qtPos = headLine.find('"')
    if not self.isEscapeOpr(headLine[:qtPos]): # 如果双引号没有被转义
     qtCnt += 1 # 双引号的数量加1
    headLine = headLine[qtPos+1:]
    # print qtCnt
   if qtCnt % 2 == 0: # 如果双引号的数量为偶数，则说明“//”是注释标志
    # print self.instr[:cmtPos]
    return self.instr[:cmtPos]
   rearLine = rearLine[slashPos+2:]
   # print rearLine
   cmtPos += 2
  # print self.instr
  return self.instr
 # 判断是否为转义字符
 def isEscapeOpr(self, instr):
  if len(instr) <= 0:
   return False
  cnt = 0
  while instr[-1] == '\\':
   cnt += 1
   instr = instr[:-1]
  if cnt % 2 == 1:
   return True
  else:
   return False
# 从json文件的路径JsonPath读取该文件，返回json对象
def loadJson(JsonPath):
 try:
  srcJson = open(JsonPath, 'r')
 except:
  print CAUTION_PRINT_HEAD + 'cannot open ' + JsonPath
  quit()
 dstJsonStr = ''
 for line in srcJson.readlines():
  if not re.match(r'\s*//', line) and not re.match(r'\s*\n', line):
   xline = xstr(line)
   dstJsonStr += xline.rmCmt()
 # print dstJsonStr
 dstJson = {}
 try:
  dstJson = json.loads(dstJsonStr)
  return dstJson
 except:
  print CAUTION_PRINT_HEAD + JsonPath + ' is not a valid json file'
  quit()
# 带缩进地在屏幕输出json字符串
def printRes(resStr):
 resStr = resStr.replace(',', ',\n')
 resStr = resStr.replace('{', '{\n')
 resStr = resStr.replace(':{', ':\n{')
 resStr = resStr.replace('}', '\n}')
 resStr = resStr.replace('[', '\n[\n')
 resStr = resStr.replace(']', '\n]')
 resStr = resStr
 resArray = resStr.split('\n')
 preBlank = ''
 for line in resArray:
  if len(line) == 0:
   continue
  lastChar = line[len(line)-1]
  lastTwoChars = line[len(line)-2:]
  if lastChar in {'}', ']'} or lastTwoChars in {'},', '],'}:
   preBlank = preBlank[:len(preBlank)-2]
  try:
   print preBlank + line.decode('utf-8')
  except:
   print(preBlank + '[%This line cannot be decoded%]')
  if lastChar == '{' or lastChar == '[':
   preBlank += ' '*2