def binary_str_to_integer(b):
    """
    Returns an int representing the conversion into decimal of the binary string entered as a parameter.
    :param: *(str)*
    :rctype: *int*
    :UC: b is a string composed of '0's and '1's
    :Examples:
    >>> binary_str_to_integer('1000')
    8
    >>> binary_str_to_integer('0')
    0
    >>> binary_str_to_integer(10001)
    Traceback (most recent call last):
    AssertionError: Entrez une chaîne de caractères!
    """
    # Test de b
    assert(type(b) == str), "Entrez une chaîne de caractères!"

    # Initialisation
    res = 0
    temp = b
    i = 0

    return int(b, 2)