Write two Python programs. One that converts a number to a Roman Numeral (roman.py), and the other converts it back to a number(namor.py). Each one should accept one or more values using sys.argv(1:).
Given a number, return a Roman Numeral string. (10 points)
Any number <= 0 or 3,999, or invalid number, return "Error".
Use only these standard values (wikipedia.org/wiki/Roman_numerals).
Assume the input is a number and not a string.
1 = I
2 = II
3 = III
4 = IV
5 = V
6 = VI
7 = VII
8 = VIII
9 = IX
10 = X
20 = XX
30 = XXX
40 = XL
50 = L
60 = LX
70 = LXX
80 = LXXX
90 = XC
100 = C
200 = CC
300 = CCC
400 = CD
500 = D
600 = DC
700 = DCC
800 = DCCC
900 = CM
1000 = M
2000 = MM
3000 = MMM
Examples:
74 = LXXIV
299 = CCXCIX
2019 = MMXIX
Examples:
roman.py 812 43 prints "812 is DCCCXII" and "43 is XLIII"
roman.py 49 5000 prints "49 is XLIX" and "5000 is Error"
Hints for Part I:
Look at thousands then hundreds then tens then ones.
Create 4 Lists and put "" for the zero values.
E.g., tens = ["", "X", "XX", "XXX", "XL", "L", …, "XC"]
Use // for integer divide and % for remainder.
Given a Roman Numeral String, parse it and return the number. If it does not match a legal number from above (in the range 1 to 3,999), return -1.
Examples:
namor.py CCCXIV prints "CCCXIV is 314"
namor.py MCMXCIX prints "MCMXCIX is 1999"
namor.py CXXXXI prints "CXXXXI is -1"
namor.py 123 MMMM II prints "123 is -1" and "MMMM is -1" and "II is 2"
Hints for Part II:
Use 4 dictionaries instead of Lists. Use dict.items() method.
E.g., tens = {"XC": 90, "LXXX": 80, "LXX": 70, …, "X": 10}
Very Important: Put each dictionary in reverse order
E.g., look for XC then LXXX then LXX then LX then L, etc.
Use the str.upper() and str.startswith() methods.
