import re
import string
#Input -> new scale -> Output
unit1 = "A^{-1} " # x A^{-1}
unit2 = "A" # x A
unit3 = "A" # x^2 A^{2}
unit4 = "A " # 1/x A^{-1}
unit5 = "A^{0.5} " # x^2 A
unit9 = "m^{1/2}" # x^2 m
#If you don't recognize the pattern, give up
# and just put some parentheses around the unit and write the transoformation:
unit6 = "m/s" # x^2 (m/s)^{2}
unit7 = "m/s^{2}" # 1/x (m/s^{2})^{-1}
unit8 = "m/s^{4}" # x^2 (m/s^{4})^{2}
[docs]def UnitConvertion(pow, unit):
"""
"""
if pow != 0:
if string.find(unit, "^") != -1: # if the unit contains a power ^
unitSplitted = re.split("\^", unit)
if string.find(unitSplitted[0], "/") != -1 or\
string.find(unitSplitted[0], "-") != -1 : # find slash /
if pow == 1:
unit = unit
else:
unit = "("+unit+")" + "^{"+ str(pow) + "}"
else:
if string.find(unitSplitted[1], "{") != -1: # if found a {
findPower = re.split("{", unitSplitted[1])
if string.find(findPower[1], "}") != -1: # found }
unitPower = re.split("}", findPower[1])
if(string.find(unitPower[0], ".") != -1):
power = float(unitPower[0]) * pow
elif(string.find(unitPower[0], "/") != -1):
#power is a float
poweSplitted = re.split("/", unitPower[0])
power = pow * int(poweSplitted[0])\
/int(poweSplitted[1])
else:
power = int(unitPower[0]) * pow
if power == 1.0:
unit = unitSplitted[0]
elif power == 0.5:
unit = unitSplitted[0] + "^{1/2}"
elif power == -0.5:
unit = unitSplitted[0] + "^{-1/2}"
else:
unit = unitSplitted[0] + "^{" + str(power) + "}"
else:
raise ValueError, "missing } in unit expression"
else: # no power
if pow != 1:
unit = "(" + unit + ")" + "^{" + str(pow) + "}"
else:
raise ValueError, "empty unit ,enter a power different from zero"
return unit
if __name__ == "__main__":
print "this unit1 %s ,its power %s , and value %s" % (unit1,
1, UnitConvertion(1, unit1))
print "this unit2 %s ,its power %s , and value %s" % (unit2, 1,
UnitConvertion(1, unit2))
print "this unit3 %s ,its power %s , and value %s" % (unit3, 2,
UnitConvertion(2, unit3))
print "this unit4 %s ,its power %s , and value %s" % (unit4, -1,
UnitConvertion(-1, unit4))
print "this unit5 %s ,its power %s , and value %s" % (unit5, 2,
UnitConvertion(2, unit5))
print "this unit6 %s ,its power %s , and value %s" % (unit6, 2,
UnitConvertion(2, unit6))
print "this unit7 %s ,its power %s , and value %s" % (unit7, -1,
UnitConvertion(-1, unit7))
print "this unit8 %s ,its power %s , and value %s" % (unit8, 2,
UnitConvertion(2, unit8))
print "this unit9 %s ,its power %s , and value %s" % (unit9, 2,
UnitConvertion(2, unit9))