Python/conversions/decimal_to_any.py
Nika Losaberidze 8bb7b8f457
Fix syntax for flake8 passing (#2096)
* Fix syntax for flake8 passing

* fixup! Format Python code with psf/black push

* # fmt: off / # fmt: on

* updating DIRECTORY.md

Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
Co-authored-by: Christian Clauss <cclauss@me.com>
2020-06-12 06:51:47 +02:00

107 lines
3.6 KiB
Python

"""Convert a positive Decimal Number to Any Other Representation"""
def decimal_to_any(num: int, base: int) -> str:
"""
Convert a positive integer to another base as str.
>>> decimal_to_any(0, 2)
'0'
>>> decimal_to_any(5, 4)
'11'
>>> decimal_to_any(20, 3)
'202'
>>> decimal_to_any(58, 16)
'3A'
>>> decimal_to_any(243, 17)
'E5'
>>> decimal_to_any(34923, 36)
'QY3'
>>> decimal_to_any(10, 11)
'A'
>>> decimal_to_any(16, 16)
'10'
>>> decimal_to_any(36, 36)
'10'
>>> # negatives will error
>>> decimal_to_any(-45, 8) # doctest: +ELLIPSIS
Traceback (most recent call last):
...
ValueError: parameter must be positive int
>>> # floats will error
>>> decimal_to_any(34.4, 6) # doctest: +ELLIPSIS
Traceback (most recent call last):
...
TypeError: int() can't convert non-string with explicit base
>>> # a float base will error
>>> decimal_to_any(5, 2.5) # doctest: +ELLIPSIS
Traceback (most recent call last):
...
TypeError: 'float' object cannot be interpreted as an integer
>>> # a str base will error
>>> decimal_to_any(10, '16') # doctest: +ELLIPSIS
Traceback (most recent call last):
...
TypeError: 'str' object cannot be interpreted as an integer
>>> # a base less than 2 will error
>>> decimal_to_any(7, 0) # doctest: +ELLIPSIS
Traceback (most recent call last):
...
ValueError: base must be >= 2
>>> # a base greater than 36 will error
>>> decimal_to_any(34, 37) # doctest: +ELLIPSIS
Traceback (most recent call last):
...
ValueError: base must be <= 36
"""
if isinstance(num, float):
raise TypeError("int() can't convert non-string with explicit base")
if num < 0:
raise ValueError("parameter must be positive int")
if isinstance(base, str):
raise TypeError("'str' object cannot be interpreted as an integer")
if isinstance(base, float):
raise TypeError("'float' object cannot be interpreted as an integer")
if base in (0, 1):
raise ValueError("base must be >= 2")
if base > 36:
raise ValueError("base must be <= 36")
# fmt: off
ALPHABET_VALUES = {'10': 'A', '11': 'B', '12': 'C', '13': 'D', '14': 'E', '15': 'F', '16': 'G', '17': 'H',
'18': 'I', '19': 'J', '20': 'K', '21': 'L', '22': 'M', '23': 'N', '24': 'O', '25': 'P',
'26': 'Q', '27': 'R', '28': 'S', '29': 'T', '30': 'U', '31': 'V', '32': 'W', '33': 'X',
'34': 'Y', '35': 'Z'}
# fmt: on
new_value = ""
mod = 0
div = 0
while div != 1:
div, mod = divmod(num, base)
if base >= 11 and 9 < mod < 36:
actual_value = ALPHABET_VALUES[str(mod)]
mod = actual_value
new_value += str(mod)
div = num // base
num = div
if div == 0:
return str(new_value[::-1])
elif div == 1:
new_value += str(div)
return str(new_value[::-1])
return new_value[::-1]
if __name__ == "__main__":
import doctest
doctest.testmod()
for base in range(2, 37):
for num in range(1000):
assert int(decimal_to_any(num, base), base) == num, (
num,
base,
decimal_to_any(num, base),
int(decimal_to_any(num, base), base),
)