1.UTF-8保存算法可以防止出现乱码，并且文件名后缀写py
2.cmd是操作window系统的，若切换别的盘则（for instance d）d: if you want to enter file please enter py+ blank space + file name if you want to return to your superior directory you enter … if you want to return root directory you enter cd if you query all directory you enter dir
3.shortcut is window+r you could open cmd
5.if you input py in cmd you will enter python interactive interface it is sign is >>>
6 py hierarchy relational from big to small package contains module,module contains statements，statements have expressins. writing expressions is intended to create and process objects.
7.type（）to find the type
8.when a variable or function is declared with two words, the underlined links are used between the two words
9 running of files in internal memory
10 the address of thee query variable uses id() function
11 to determine whether the values are equal use ‘==’,and detemine whether the addresses are the same，use ‘is’
12 integers under 256 have been cached by python,that is different variables refer to them,but their addresses are the same 13 the length of a string can be measured using the built-in function len() 15 string can be added ，string and numbers can be mulitiplied 16 the declaration of the data type variable is as follows 17 the core data types are summarized as follows
