def base2tobase10(value):
    """
    This function converts from base 2 to base 10.  Unlike base10tobase2,
    there is no zfill option, and the result is output as an int.

    """
    new_value = 0
    val = str(value)
    if val < 0:
        neg = True
        val *= -1
    else:
        neg = False
    val = str(value)
    factor = 0
    for i in range(len(val) - 1, -1, -1):
        if not val[i] == '-':
            new_value += int(val[i]) * pow(2, factor)
        else:
            neg = True
        factor += 1
    if neg:
        new_value *= -1
    return new_value
