python 的数值和字符串和相关内建函数
内建函数:
divmod,值和字符返回商和余数
模块:
In [17]: from __future__ import division
In [18]: 5/2
Out[18]: 2.5
In [19]: 9/2
Out[19]: 4.5
In [20]: 9.0/2
Out[20]: 4.5
In [21]: 9/2.0
Out[21]: 4.5
得到浮点数的亿华云串和结果
数值类型:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 In [1]: 2 ** 31 Out[1]: 2147483648 In [2]: a=99999999999999999999999999999999999999999 In [3]: a Out[3]: 99999999999999999999999999999999999999999L In [4]: type(a) Out[4]: long In [5]: 3/2 Out[5]: 1 In [7]: 3.0/2 Out[7]: 1.5 In [8]: type(3.0/2) Out[8]: float In [9]: a=23j In [10]: type(a) Out[10]: complex In [11]:字符串:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 In [21]: a=abcde In [22]: a Out[22]: abcde In [23]: a[0] Out[23]: a In [24]: a[4] Out[24]: e In [25]: a[-1] Out[25]: e In [26]: a[0]+[1] In [27]: a[0]+a[1] Out[27]: ab In [28]: a[0:2] Out[28]: ab In [29]: a[:2] Out[29]: ab In [30]: a[1:] Out[30]: bcde In [31]: a[::] Out[31]: abcde In [32]: a[:-1] Out[32]: abcd In [33]: a[::1] Out[33]: abcde In [34]: a[::2] Out[34]: ace In [35]: a[:] Out[35]: abcde In [36]: a[-4:-2] Out[36]: bc In [37]: a[-2:-4:-1] Out[37]: dc云服务器