| 1 | """ |
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| 2 | Convert units to strings that can be displayed |
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| 3 | This is a cleaned up version of unitConverter.py |
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| 4 | """ |
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| 5 | import re |
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| 6 | import string |
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| 7 | |
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| 8 | def convert_unit(power, unit): |
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| 9 | """ |
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| 10 | Convert units to strings that can be displayed |
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| 11 | """ |
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| 12 | if power != 0: |
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| 13 | if string.find(unit, "^") != -1: # if the unit contains a powerer ^ |
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| 14 | toks = re.split("\^", unit) |
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| 15 | if string.find(toks[0], "/") != -1 or \ |
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| 16 | string.find(toks[0], "-") != -1: |
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| 17 | if power == 1: |
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| 18 | unit = unit |
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| 19 | else: |
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| 20 | unit = "(" + unit + ")" + "^{" + str(power) + "}" |
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| 21 | else: |
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| 22 | if string.find(toks[1], "{") != -1: # if found a { |
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| 23 | find_power_toks = re.split("{", toks[1]) |
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| 24 | if string.find(find_power_toks[1], "}") != -1: # found } |
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| 25 | unit_toks = re.split("}", find_power_toks[1]) |
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| 26 | if string.find(unit_toks[0], ".") != -1: |
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| 27 | powerer = float(unit_toks[0]) * power |
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| 28 | elif string.find(unit_toks[0], "/") != -1: |
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| 29 | power_toks = re.split("/", unit_toks[0]) |
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| 30 | powerer = power * int(power_toks[0])\ |
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| 31 | / int(power_toks[1]) |
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| 32 | else: |
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| 33 | powerer = int(unit_toks[0]) * power |
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| 34 | |
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| 35 | if powerer == 1.0: |
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| 36 | unit = toks[0] |
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| 37 | elif powerer == 0.5: |
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| 38 | unit = toks[0] + "^{1/2}" |
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| 39 | elif powerer == -0.5: |
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| 40 | unit = toks[0] + "^{-1/2}" |
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| 41 | else: |
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| 42 | unit = toks[0] + "^{" + str(powerer) + "}" |
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| 43 | else: |
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| 44 | raise ValueError, "missing } in unit expression" |
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| 45 | else: # no powerer |
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| 46 | if power != 1: |
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| 47 | unit = "(" + unit + ")" + "^{" + str(power) + "}" |
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| 48 | else: |
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| 49 | raise ValueError, "empty unit ,enter a powerer different from zero" |
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| 50 | return unit |
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| 51 | |
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| 52 | |
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| 53 | if __name__ == "__main__": |
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| 54 | # pylint: disable=invalid-name |
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| 55 | # Input -> new scale -> Output |
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| 56 | unit1 = "A^{-1} " # x A^{-1} |
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| 57 | unit2 = "A" # x A |
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| 58 | unit3 = "A" # x^2 A^{2} |
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| 59 | unit4 = "A " # 1/x A^{-1} |
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| 60 | unit5 = "A^{0.5} " # x^2 A |
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| 61 | unit9 = "m^{1/2}" # x^2 m |
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| 62 | |
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| 63 | # If you don't recognize the pattern, give up |
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| 64 | # and just put some parentheses around the unit and write the transoformation: |
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| 65 | |
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| 66 | unit6 = "m/s" # x^2 (m/s)^{2} |
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| 67 | unit7 = "m/s^{2}" # 1/x (m/s^{2})^{-1} |
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| 68 | unit8 = "m/s^{4}" # x^2 (m/s^{4})^{2} |
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| 69 | |
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| 70 | print "this unit1 %s ,its powerer %s , and value %s" % (unit1, 1, convert_unit(1, unit1)) |
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| 71 | print "this unit2 %s ,its powerer %s , and value %s" % (unit2, 1, convert_unit(1, unit2)) |
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| 72 | print "this unit3 %s ,its powerer %s , and value %s" % (unit3, 2, convert_unit(2, unit3)) |
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| 73 | print "this unit4 %s ,its powerer %s , and value %s" % (unit4, -1, convert_unit(-1, unit4)) |
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| 74 | print "this unit5 %s ,its powerer %s , and value %s" % (unit5, 2, convert_unit(2, unit5)) |
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| 75 | print "this unit6 %s ,its powerer %s , and value %s" % (unit6, 2, convert_unit(2, unit6)) |
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| 76 | print "this unit7 %s ,its powerer %s , and value %s" % (unit7, -1, convert_unit(-1, unit7)) |
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| 77 | print "this unit8 %s ,its powerer %s , and value %s" % (unit8, 2, convert_unit(2, unit8)) |
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| 78 | print "this unit9 %s ,its powerer %s , and value %s" % (unit9, 2, convert_unit(2, unit9)) |
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