Job #
1. What is the programming language?
2. What is programming?
3. Why programming?
4. Computer five were composed What is the role?
The mechanical hard drive works?
6. qq start the process?
7. Define the principle of internal variables
8. Variable three elements
9. The variable naming convention
10. The garbage collection
# A
1. What is the programming language
Language: Information exchange carrier
People write, the computer can understand; it can borrow and use computer programming language is the language of communication
2. What is programming
Programming: writing computer can recognize the language, and computer to exchange control computer to do things
3, why should Programming
Computer to work by identifying the programming language, let the computer do the work instead of people, the liberation of the human
4, consisting of five computer role
Controller, the arithmetic unit, memory, input devices, output devices
The controller: controls the entire computer system, the role of coordination and control
Operator: logical and arithmetic operations
Memory: store data
The input device (input): receiving external information, and converted into a machine language recognized save up
An output device (output): The computer's processing results, showing it in a suitable manner
5, mechanical hard disk works
Small motor driven pointer rotation, head to access the data
6, QQ start the process
① QQ user double-clicks the icon to start the program
② the open operating system commands transmitted to the CPU, CPU control program from the hard drive to start QQ memory
③ CPU began to explain QQ program, interpreter in ...
④ CPU processing result via an output device to show the effect of QQ login
7, internal principles defined variables
① apply a memory space in memory, the value placed into
② the value of the variable binding
Note that there is a small integer ③ pool, Python when defining int type variables, in order to avoid multiple applications to reduce memory efficiency,
Open interpreter when direct integer [-5.256] in advance for the good fixed memory space, regardless of the value of a bind any variable names, memory addresses will not change.
Pool small integer range than the IDE editor interpreter application to large
8, the three elements of variable
① Id (): id (variable name) returned a bunch of numbers, can be understood as a variable memory address corresponding to memory worth
② type (): type (variable name) returns the data type of the variable
③ value: is the value corresponding to the variable memory
9, variable naming convention
① two styles: Hump body and underscore
② variable, formed from any combination of alphanumeric characters and underscores, and can not begin with a number
Form ③ Chinese, English, Pinyin are not being given, but try to be in English, and see the word meaning knowledge
10, garbage collection
① reference count: When a value of the memory variable name is not bound, to be recovered
② labeled Clear: When memory is going to fill up an application, start the recovery mechanism
③ generational recovery: recovery mechanisms multiple scans memory usage, for doing worthwhile survival statistics, the higher the survival rate is lower scanning frequency of it is less likely to be recovered