python: add Sample class to parse villas.human format

python/villas/node/sample.py

@@ -0,0 +1,83 @@
+import re
+
+class Timestamp:
+	"""Parsing the VILLASnode human-readable timestamp format"""
+
+	def __init__(self, seconds = 0, nanoseconds = None, offset = None, sequence = None):
+		self.seconds = seconds
+		self.nanoseconds = nanoseconds
+		self.offset = offset
+		self.sequence = sequence
+
+	@classmethod
+	def parse(self, ts):
+		m = re.match('(\d+)(?:\.(\d+))?([-+]\d+(?:\.\d+)?(?:e[+-]?\d+)?)?(?:\((\d+)\))?', ts)
+
+		seconds		= int(m.group(1)); # Mandatory
+		nanoseconds	= int(m.group(2))   if m.group(2) else None
+		offset		= float(m.group(3)) if m.group(3) else None
+		sequence	= int(m.group(4))   if m.group(4) else None
+
+		return Timestamp(seconds, nanoseconds, offset, sequence)
+
+	def __str__(self):
+		str = "%u" % (self.seconds)
+
+		if self.nanoseconds is not None:
+			str += ".%09u" % self.nanoseconds
+		if self.offset is not None:
+			str += "+%u" % self.offset
+		if self.sequence is not None:
+			str += "(%u)" % self.sequence
+
+		return str
+
+	def __float__(self):
+		sum = float(self.seconds)
+
+		if self.nanoseconds is not None:
+			sum += self.nanoseconds * 1e-9
+		if self.offset is not None:
+			sum += self.offset
+
+		return sum
+
+	def __cmp__(self, other):
+		return cmp(float(self), float(other))
+
+class Sample:
+	"""Parsing a VILLASnode sample from a file (not a UDP package!!)"""
+
+	def __init__(self, ts, values):
+		self.ts = ts
+		self.values = values
+
+	@classmethod
+	def parse(self, line):
+		csv = line.split()
+
+		ts = Timestamp.parse(csv[0])
+		vs = [ ]
+
+		for value in csv[1:]:
+			try:
+				v = float(value)
+			except ValueError:
+				value = value.lower()
+				try:
+					v = complex(value)
+				except:
+					if value.endswith('i'):
+						v = complex(value.replace('i', 'j'))
+					else:
+						raise ValueError()
+
+			vs.append(v)
+
+		return Sample(ts, vs)
+
+	def __str__(self):
+		return '%s %s' % (self.ts, " ".join(map(str, self.values)))
+
+	def __cmp__(self, other):
+		return cmp(self.ts, other.ts)