ading a converter from SI units to float. Rought but does the job.

pykat/SIfloat.py

+import os
+import re
+
+"""
+class SIfloat(value):
+     def __init__(self, value):
+        self.__value = value
+"""     
+
+#staticmethod
+def SIfloat(value):
+    value=str(value)
+
+    __prefix = {'y': 1e-24,  # yocto
+                'z': 1e-21,  # zepto
+                'a': 1e-18,  # atto
+                'f': 1e-15,  # femto
+                'p': 1e-12,  # pico
+                'n': 1e-9,   # nano
+                'u': 1e-6,   # micro
+                'm': 1e-3,   # mili
+                'c': 1e-2,   # centi
+                'd': 1e-1,   # deci
+                'k': 1e3,    # kilo
+                'M': 1e6,    # mega
+                'G': 1e9,    # giga
+                'T': 1e12,   # tera
+                'P': 1e15,   # peta
+                'E': 1e18,   # exa
+                'Z': 1e21,   # zetta
+                'Y': 1e24,   # yotta
+                }
+    for i, j in __prefix.iteritems():
+        value=value.replace(i, str(j))
+    return float(value)
+