Python Learning notes-brother Ma 2017

Programming Languages

1, Users:
Problem space
2. Computer: Problem Solving
Solution Space
Abstract
Machine code-> microcode Language-> Advanced language function

Shell programming
Control Language: Glue language
Frame: Web,django
BYTE code: Bytecode Python code language first touch python run

Source code (. py)
Comolier (PVM programming virtual machine)
Bytecode (. PYc)
Interpreter (PVM execution virtual machine)
Processor Python Implementation

CPython: The way to achieve the original and standard
Jython: implementation for integration with the Java language
IronPython: Implementing Python performance optimization tools for integration with the. NET Framework

Psyco: Expansion module, algorithm optimization, replaced by pypy
Pypy:python interpreter, dynamic compiler
Shed Skin: Compilers, converting to optimized C + + code to write, execute Python code

Interactive interpreter: Start Python directly
Python Program Files (. py)
Example:

#!/usr/bin/python  #解析器
import platform    #导入python模块
print platform.uname ()  #打印uname结果

Linux Run Results:

root@kali:~/Desktop/python_pratice# chmod +x firstcode.py root@kali:~/
desktop/python_pratice#./firstcode.py
(' Linux ', ' Kali ', ' 4.3.0-kali1-amd64 ', ' #1 SMP Debian 4.3.3-5kali4 (2016-01-13) ', ' x86_64 ', ' "
root@kali:~/desktop/python _pratice#

Python programs can be decomposed into modules, statements, expressions, and objects

Idle tools:
Eclipse and Pydev
Python win
Komodo
Wingware
Pycharm Expansion:

Process oriented:
Command-centric, processing data by instructions
How to organize your code to solve problems
Object oriented:
In the data center, all the processing code is spread around the data
If the data structure is designed to organize the information and provide a quick start data structure for the processing of python process-type programming in this type of data

A collection of data elements organized together in a way that can be numbers or characters, or even other data structures;
Python's most basic data structure is a sequence; a
series of data in Python's 6: Lists, tuples, strings, Unicode strings, Buffer object and Xrange object;

key elements of Python underlying data type

Integral type: Integral (immutable Type), Boolean
floating-point type: floating-point, plural, decimal numeric
string

object Reference (variable)

Python saves all data as a memory object
in Python, the variable is actually pointing to the memory object
"=" to bind the variable name to an object in the inner, such as if the object existed beforehand, to bind directly, otherwise the referenced object is created by "="

Combining data Types

Sequence type: list []-variable sequence, tuple ()-immutable sequence, String
collection type: Collection
map type: Dictionary

logical operation type

Identity operator: is
comparison operator: <,>,<=,>=,!=,==
member Operator: In or not in
logical operator: And,or,not

Control Flow Statement

If
while
for...in
try

arithmetic operator Input/Output

Output: Python3-print () function, python2-print statement
input: input (), raw_input ()
# # #函数的创建与调用