regex-function convert roman numerals

[weberr]

Has anyone created a function to convert roman numerals to Arabic, and vice versus?
Or help me to learn how to create such a function?

[JSWolf]

There is no way to convert I to 1 without also converting the word I. So that's out for sure. You would have to do I by doing a manual search/replace.

[BetterRed]

Originally Posted by weberr

Has anyone created a function to convert roman numerals to Arabic, and vice versus?
Or help me to learn how to create such a function?

@weberr - Here's the python code ==>> To and From Roman and Integer

Maybe it could be wrangled onto a regex function;

BR

[kovidgoyal]

It should be fairly trivial, I outlined a solution in this thread: https://www.mobileread.com/forums/sho...d.php?t=244255

for uppercasing roman numerals. Converting them to arabic is similar, a bit of googling will find you a python function to do the actual conversion.

The only major problem would be dealing with small numbers, the dictionary based approach will probably not work well for numbers of less than three digits, so you would need to special case them.

[jbacelar]

What I use.

Arabic to Roman
Search (eg):
(>Chapter )(\d+)(<)

Regex-function:

def num_roman(input):
    ints = (1000, 900,  500, 400, 100,  90, 50,  40, 10,  9,   5,  4,   1)
    nums = ('M',  'CM', 'D', 'CD','C', 'XC','L','XL','X','IX','V','IV','I')
    result = ""
    input=int(input)
    for i in range(len(ints)):
        count = input//ints[i]
        result += nums[i] * count
        input -= ints[i] * count
    return result
def replace(match, number, file_name, metadata, dictionaries, data, functions, *args, **kwargs):
    return match.group(1)+str(num_roman(match.group(2)))+match.group(3)

Roman to Arabic
Search (eg):
(>Chapter )(.+?)(<)

Regex-function:

numeral_map = zip(
    (1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1),
    ('M', 'CM', 'D', 'CD', 'C', 'XC', 'L', 'XL', 'X', 'IX', 'V', 'IV', 'I')
)
	   
def arabic_num(n):
    n = unicode(n).upper()
    i = result = 0
    for integer, numeral in numeral_map:
        while n[i:i + len(numeral)] == numeral:
            result += integer
            i += len(numeral)
    return result
def replace(match, number, file_name, metadata, dictionaries, data, functions, *args, **kwargs):
    return match.group(1)+str(arabic_num(match.group(2)))+match.group(3)

[JSWolf]

Originally Posted by jbacelar

What I use.

Arabic to Roman
Search (eg):
(>Chapter )(\d+)(<)

Regex-function:

def num_roman(input):
    ints = (1000, 900,  500, 400, 100,  90, 50,  40, 10,  9,   5,  4,   1)
    nums = ('M',  'CM', 'D', 'CD','C', 'XC','L','XL','X','IX','V','IV','I')
    result = ""
    input=int(input)
    for i in range(len(ints)):
        count = input//ints[i]
        result += nums[i] * count
        input -= ints[i] * count
    return result
def replace(match, number, file_name, metadata, dictionaries, data, functions, *args, **kwargs):
    return match.group(1)+str(num_roman(match.group(2)))+match.group(3)

Roman to Arabic
Search (eg):
(>Chapter )(.+?)(<)

Regex-function:

numeral_map = zip(
    (1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1),
    ('M', 'CM', 'D', 'CD', 'C', 'XC', 'L', 'XL', 'X', 'IX', 'V', 'IV', 'I')
)
	   
def arabic_num(n):
    n = unicode(n).upper()
    i = result = 0
    for integer, numeral in numeral_map:
        while n[i:i + len(numeral)] == numeral:
            result += integer
            i += len(numeral)
    return result
def replace(match, number, file_name, metadata, dictionaries, data, functions, *args, **kwargs):
    return match.group(1)+str(arabic_num(match.group(2)))+match.group(3)

And do you then go back and fix every occurrence of the WORD I changed to a 1?

[jbacelar]

Originally Posted by JSWolf

And do you then go back and fix every occurrence of the WORD I changed to a 1?

I use it to change things as these:
Chapter 22, which changes to Chapter XXII.
O Chapter XXII, which changes to Chapter 22.
Also for the notes, as [22] changes to [XXII] and vice versa.
As you can see, I will not go to fix anything later.
It is a matter of imagination and cleverness to search.

[JSWolf]

Originally Posted by jbacelar

I use it to change things how are you:
Chapter 22, which changes to Chapter XXII.
O Chapter XXII, which changes to Chapter 22.
Also for the notes, as [22] changes to [XXII] and vice versa.
As you can see, I will not go to fix anything later.
It is a matter of imagination and cleverness to search.

Yes, if you can find text or code in front of the I that will differentiate an I (1) from an I, then yes, it will work. But if you don't have anything you can use to differentiate then it will be a problem.

[theducks]

Originally Posted by JSWolf

Yes, if you can find text or code in front of the I that will differentiate an I (1) from an I, then yes, it will work. But if you don't have anything you can use to differentiate then it will be a problem.

The example S&R will not touch the body of the work. It looks for "Chapter\s followed by a Roman Number

If you want to be sloppy, I guess you would have to worry about your
"I worry that this will become..."
"1 worry that this became..."

[BetterRed]

Originally Posted by JSWolf

Yes, if you can find text or code in front of the I that will differentiate an I (1) from an I, then yes, it will work. But if you don't have anything you can use to differentiate then it will be a problem.

If you had your wits about you then you wouldn't use the function indiscriminately

The editor provides a checkpointing facility for use by witful users who want to dodge the bullets they aim at their feet, but in the final washup there is nothing one can do to protect the witless from their witlessness.

Originally Posted by theducks

If you want to be sloppy, I guess you would have to worry about your
"I worry that this will become..."
"1 worry that this became..."

If you worry about whatever became of 'will become' then your troubles haven't even begun ==>> English verb become conjugated in all tenses.

BR

[weberr]

Thanks. Works for me -- as long as you 'replace all'
Nice piece of work

Originally Posted by jbacelar

What I use.

Arabic to Roman
Search (eg):
(>Chapter )(\d+)(<)

Regex-function:

def num_roman(input):
    ints = (1000, 900,  500, 400, 100,  90, 50,  40, 10,  9,   5,  4,   1)
    nums = ('M',  'CM', 'D', 'CD','C', 'XC','L','XL','X','IX','V','IV','I')
    result = ""
    input=int(input)
    for i in range(len(ints)):
        count = input//ints[i]
        result += nums[i] * count
        input -= ints[i] * count
    return result
def replace(match, number, file_name, metadata, dictionaries, data, functions, *args, **kwargs):
    return match.group(1)+str(num_roman(match.group(2)))+match.group(3)

Roman to Arabic
Search (eg):
(>Chapter )(.+?)(<)

Regex-function:

numeral_map = zip(
    (1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1),
    ('M', 'CM', 'D', 'CD', 'C', 'XC', 'L', 'XL', 'X', 'IX', 'V', 'IV', 'I')
)
	   
def arabic_num(n):
    n = unicode(n).upper()
    i = result = 0
    for integer, numeral in numeral_map:
        while n[i:i + len(numeral)] == numeral:
            result += integer
            i += len(numeral)
    return result
def replace(match, number, file_name, metadata, dictionaries, data, functions, *args, **kwargs):
    return match.group(1)+str(arabic_num(match.group(2)))+match.group(3)

I know it's been a while, but I just found this and want to thank you for posting. All I had to do to get it to work was to change unicode to str.