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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def Regions(self, skip_mapped_files=False, skip_shared_regions=False, skip_executable_regions=False, skip_readonly_regions=False):
 """Returns an iterator over the readable regions for this process."""

    try:
      maps_file = open("/proc/" + str(self.pid) + "/maps", "r")
    except OSError as e:
      raise process_error.ProcessError(e)

    with maps_file:
      for line in maps_file:
        m = self.maps_re.match(line)
        if not m:
          continue
        start = int(m.group(1), 16)
        end = int(m.group(2), 16)
        region_protec = m.group(3)
        inode = int(m.group(6))

        if "r" in region_protec:
          if skip_mapped_files and inode != 0:
            continue
          if skip_shared_regions and "s" in region_protec:
            continue
          if skip_executable_regions and "x" in region_protec:
            continue
          if skip_readonly_regions and "w" not in region_protec:
            continue
          yield start, end - start