#### Decimal to Binary

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```"""Convert a Decimal Number to a Binary Number."""

def decimal_to_binary_iterative(num: int) -> str:
"""
Convert an Integer Decimal Number to a Binary Number as str.
>>> decimal_to_binary_iterative(0)
'0b0'
>>> decimal_to_binary_iterative(2)
'0b10'
>>> decimal_to_binary_iterative(7)
'0b111'
>>> decimal_to_binary_iterative(35)
'0b100011'
>>> # negatives work too
>>> decimal_to_binary_iterative(-2)
'-0b10'
>>> # other floats will error
>>> decimal_to_binary_iterative(16.16) # doctest: +ELLIPSIS
Traceback (most recent call last):
...
TypeError: 'float' object cannot be interpreted as an integer
>>> # strings will error as well
>>> decimal_to_binary_iterative('0xfffff') # doctest: +ELLIPSIS
Traceback (most recent call last):
...
TypeError: 'str' object cannot be interpreted as an integer
"""

if isinstance(num, float):
raise TypeError("'float' object cannot be interpreted as an integer")
if isinstance(num, str):
raise TypeError("'str' object cannot be interpreted as an integer")

if num == 0:
return "0b0"

negative = False

if num < 0:
negative = True
num = -num

binary: list[int] = []
while num > 0:
binary.insert(0, num % 2)
num >>= 1

if negative:
return "-0b" + "".join(str(e) for e in binary)

return "0b" + "".join(str(e) for e in binary)

def decimal_to_binary_recursive_helper(decimal: int) -> str:
"""
Take a positive integer value and return its binary equivalent.
>>> decimal_to_binary_recursive_helper(1000)
'1111101000'
>>> decimal_to_binary_recursive_helper("72")
'1001000'
>>> decimal_to_binary_recursive_helper("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 decimal_to_binary_recursive_helper(div) + str(mod)

def decimal_to_binary_recursive(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.
>>> decimal_to_binary_recursive(0)
'0b0'
>>> decimal_to_binary_recursive(40)
'0b101000'
>>> decimal_to_binary_recursive(-40)
'-0b101000'
>>> decimal_to_binary_recursive(40.8)
Traceback (most recent call last):
...
ValueError: Input value is not an integer
>>> decimal_to_binary_recursive("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{decimal_to_binary_recursive_helper(int(number))}"

if __name__ == "__main__":
import doctest

doctest.testmod()

print(decimal_to_binary_recursive(input("Input a decimal number: ")))
```