寫個兩個簡單的函式給你參考

# 十進制轉二進制（輸入整數，輸出字串）
def decimalToBinary(number):
    output = ""
    # 處理32個位元(4 bytes)
    for i in range(0, 32):
        if number & (1 << i):
            output = "1" + output
        else:
            output = "0" + output
    # 把左邊不需要的0刪掉
    output = output.lstrip("0")
    return "0b" + output

# 二進制轉十進制（輸入0b開頭的字串，輸出數字）
def binaryToDecimal(binary):
    if not binary.startswith("0b"):
        raise Exception('must start with "0b"')
    
    output = 0;
    binaryLen = len(binary)
    for i in range(0, binaryLen - 2):
        if binary[binaryLen - 1 - i] != "0":
            output += 1 << i
    return output

測試

print("15 => " + decimalToBinary(15))
print("0b1111 => " + str(binaryToDecimal("0b1111")))
print("321 => " + decimalToBinary(321))
print("0b101000001 => " + str(binaryToDecimal("0b101000001")))

結果

15 => 0b1111
0b1111 => 15
321 => 0b101000001
0b101000001 => 321