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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
