int文档

文档

class int(object):
    """
    int(x=0) -> integer
    int(x, base=10) -> integer
    ----------------------------------------------------------------------------------
    Convert a number or string to an integer, or return 0 if no arguments
    are given.  If x is a number, return x.__int__().  For floating point
    numbers, this truncates towards zero.
    将一个数字或者字符串（str.isNum==True），如果没有给参数，默认为0（如print(int())结果为0）
    如果参数x是一个数字，则返回x.__int__()的结果，如果是一个浮点数，则会只取整数，
    (如print(int(2.5))的结果为2)
    ----------------------------------------------------------------------------------
    If x is not a number or if base is given, then x must be a string,
    bytes, or bytearray instance representing an integer literal in the
    given base.  The literal can be preceded by '+' or '-' and be surrounded
    by whitespace.  The base defaults to 10.  Valid bases are 0 and 2-36.
    Base 0 means to interpret the base from the string as an integer literal.
    >>> int('0b100', base=0)
    4
    base参数为进制，默认为10进制
    """

    def bit_length(self):  # real signature unknown; restored from __doc__
        """
        int.bit_length() -> int
        ----------------------------------------------------------------------------------
        返回一个int数转换为二进制后至少要用多少位来表示，返回值为int类型
        Number of bits necessary to represent self in binary.
        数字必须转换为二进制后再计算
        ----------------------------------------------------------------------------------
        >>> bin(37)
        '0b100101'
        >>> (37).bit_length()
        6
        如：37的二进制为'0b100101'（6位），那么37的bit_length()结果为6
        ----------------------------------------------------------------------------------
        """
        return 0

　　

示例

print(int())            # 结果为0
print(int(2.5))         # 结果为

n = 250
n_bytes = bin(n)
print(n_bytes)          # 结果为0b11111010
print(n.bit_length())   # 结果为8

print(int('0b1010',base=0)) # 结果为10