Python/conversions/decimal_to_binary_recursion.py at master · imanghotbi-python/Python · GitHub

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defbinary_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)
ifdecimalin (0, 1): # Exit cases for the recursion
returnstr(decimal)
div, mod=divmod(decimal, 2)
returnbinary_recursive(div) +str(mod)


defmain(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()
ifnotnumber:
raiseValueError("No input value was provided")
negative="-"ifnumber.startswith("-") else""
number=number.lstrip("-")
ifnotnumber.isnumeric():
raiseValueError("Input value is not an integer")
returnf"{negative}0b{binary_recursive(int(number))}"


if__name__=="__main__":
fromdoctestimporttestmod

testmod()