FilesExpand file tree

master

/

decimal_to_binary_recursion.py

Copy path

Blame

More file actions

Blame

More file actions

Latest commit

 

History

History

History

53 lines (48 loc) · 1.5 KB

master

/

decimal_to_binary_recursion.py

Copy path

Top

File metadata and controls

• Code
• Blame

53 lines (48 loc) · 1.5 KB

Raw

Copy raw file

Download raw file

Open symbols panel

Edit and raw actions

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

def binary_recursive(decimal: int) -> str:

"""

Take a positive integer value and return its binary equivalent.

>>> binary_recursive(1000)

'1111101000'

>>> binary_recursive("72")

'1001000'

>>> binary_recursive("number")

Traceback (most recent call last):

...

ValueError: invalid literal for int() with base 10: 'number'

"""

decimal = int(decimal)

if decimal in (0, 1): # Exit cases for the recursion

return str(decimal)

div, mod = divmod(decimal, 2)

return binary_recursive(div) + str(mod)

def main(number: str) -> str:

"""

Take an integer value and raise ValueError for wrong inputs,

call the function above and return the output with prefix "0b" & "-0b"

for positive and negative integers respectively.

>>> main(0)

'0b0'

>>> main(40)

'0b101000'

>>> main(-40)

'-0b101000'

>>> main(40.8)

Traceback (most recent call last):

...

ValueError: Input value is not an integer

>>> main("forty")

Traceback (most recent call last):

...

ValueError: Input value is not an integer

"""

number = str(number).strip()

if not number:

raise ValueError("No input value was provided")

negative = "-" if number.startswith("-") else ""

number = number.lstrip("-")

if not number.isnumeric():

raise ValueError("Input value is not an integer")

return f"{negative}0b{binary_recursive(int(number))}"

if __name__ == "__main__":

from doctest import testmod

testmod()