https://github.com/janjoswig/ancient
Convert between integers and roman numerals in Python
https://github.com/janjoswig/ancient
Last synced: 2 months ago
JSON representation
Convert between integers and roman numerals in Python
- Host: GitHub
- URL: https://github.com/janjoswig/ancient
- Owner: janjoswig
- License: mit
- Created: 2020-12-15T06:34:48.000Z (over 4 years ago)
- Default Branch: main
- Last Pushed: 2021-02-25T09:48:12.000Z (over 4 years ago)
- Last Synced: 2025-03-10T16:39:48.014Z (3 months ago)
- Language: Python
- Size: 79.1 KB
- Stars: 1
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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# Ancient
Convert between integers and Roman numerals in Python
## Install
Install from PyPi
```bash
$ pip install ancient
```
or clone the developement version from GitHub
```bash
$ git clone https://github.com/janjoswig/Ancient.git
$ cd Ancient
$ pip install .
```
## Usage
### Import
```python
from ancient import roman
```
### Basic conversions
Convert integer values to Roman numerals
```python
for i in range(10):
print(roman.roman(i))
```
```bash
N
I
II
III
IV
V
VI
VII
VIII
IX
```
By default, the conversion follows the standard scheme using a subtractive representation for the values 4, 9, 14, etc. (e.g. IV instead of IIII). An additive representation can be selected via the `mapping` keyword (see also [Custom Mappings](#Mappings)).
```python
for i in range(10):
print(roman.roman(i, mapping="ascii-additive"))
```
```bash
N
I
II
III
IIII
V
VI
VII
VIII
VIIII
```
Composition of large numbers (>4999) can be improved using an extended mapping.
```python
for i in [5000, 10000, 50000, 100000]:
print(roman.roman(i, mapping="unicode-extended"))
```
```bash
ↁ
ↂ
ↇ
ↈ
```
Interpretation of Roman numerals
```python
for i in ["I", "IV", "IIII", "XX", "XL", "C"]:
print(roman.interpret_roman(i))
```
```bash
1
4
4
20
40
100
```
### The Roman data type
The packag provides the `Roman` data type to handle Roman numerals
```python
number = roman.Roman(5)
print(f"{number!r}")
print(f"{number!s}")
```
```bash
Roman(5, format='ascii-std')
V
```
The type behaves like an integer in arithmetic operations
```python
print(number + 2)
print(number - roman.Roman(1))
print(number * 2)
print(number / 2) # Integer division!
```
```bash
VII
IV
X
II
```
A mapping of Roman symbols to integer values used for interconversions has the form
```python
mapping = {
"M": 1000,
"D": 500,
"C": 100,
"L": 50,
}
```
For the conversion of integers to Roman numerals, such a mapping should have a decreasing order in the integer values. To ensure this, mappings can inherit from `roman.Symbols`. Note, that only one symbol is effectively used if the same value is mapped to more than one symbols.
```python
custom_mapping = roman.Symbols()
custom_mapping.update({"ↆ": 50, "Ж": 100, "I": 1, "Ʌ": 5})
print(custom_mapping)
```
```bash
{'Ж': 100, 'ↆ': 50, 'Ʌ': 5, 'I': 1}
```
A cutsom mapping can be used in conversions instead of the default mappings
```python
roman.roman(156, mapping=custom_mapping)
```
```bash
'ЖↆɅI'
```
A set of mappings is provided as instances of f `roman.Symbols` in `roman.symbols`
```python
print(roman.symbols.keys())
```
```bash
dict_keys(['ascii-additive', 'ascii-std', 'ascii-variant', 'unicode-additive', 'unicode-std', 'unicode-extended', 'unicode-extended-claudian'])
```
Mappings stored in this place can be used by their key in conversions. Instances of type `Roman` have an attribute `format` that controls the conversion and should be a valid mapping key.
```python
number = roman.Roman(100)
print(number)
roman.symbols["custom"] = custom_mapping
number.format = "custom"
print(number)
```
```bash
C
Ж
```
### Zero and negative numbers
The package can handle negative numbers
```python
number = roman.Roman(-10)
print(number)
```
```bash
-X
```
The symbol used to represent 0 is stored on the used mappings and can be changed.
```python
print(roman.symbols["unicode-std"].nullum)
```
```bash
N
```