decimal_to_binary() should return identical values as bin()

[cclauss]

Python/conversions/decimal_to_binary.py

Line 4 in 7b267e5

def decimal_to_binary(num):

Please change decimal_to_binary() to return identical values as the Python builtin bin(). With doctests to prove it please.

@PatOnTheBack @Corruption13

[syedwaleedhyder]

Give an example of a decimal number for which decimal_to_binary(num) is inconsistent.

[cclauss]

0b is missing

[syedwaleedhyder]

I have created a pull request(#1093).
The new code can handle ZERO and negative numbers too.