python怎么定义int

首先python不是强类型语言。

所以不需要声明类型

a = 3 会自动识别3是int整型。

int()是Python的一个内部函数

Python系统帮助里面是这么说的

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help(int)
Help on class int in module __builtin__:

class int(object)
| int(x[, base]) -> integer
|
| Convert a string or number to an integer, if possible. A floating point
| argument will be truncated towards zero (this does not include a string
| representation of a floating point number!) When converting a string, use
| the optional base. It is an error to supply a base when converting a
| non-string. If base is zero, the proper base is guessed based on the
| string content. If the argument is outside the integer range a
| long object will be returned instead.

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int(12.0)

12

int()函数可以将一个数转化为整数
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int('12',16)

18

这里有两个地方要注意：1）12要以字符串的形式进行输入，如果是带参数base的话
2）这里并不是将12转换为16进制的数，而是说12就是一个16进制的数，int()函数将其用十进制数表示，如下
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int('0xa',16)

10

int('10',8)

8