_1 python syntax of basic grammar Overview

 
 http://www.runoob.com/python3 

 
 Chapter: Tutorial, basic syntax, data types, interpreter, comment, operator, 

 
 Outline 

View python version
Implement a python3.x program, hello world
Encoding format
Identifier (i.e., class names, method names)
python reserved word (keyword library)
Note
Line with the indentation
Multi-line statement
Numeric type (Number) (int, bool, float, complex)
String (String)
Blank line
Waiting for user input
The same line shows multiple statements, use a semicolon division
Multiple statements constitute code groups (like if, while, def and class this compound statement, the first line to start with keywords, a colon (:) end, after the bank constitute one or more lines of code code group)
Print output
import和from...import
Command line parameters

 
 text 

 
 Print output 

  The default print output is the new line, if you want to achieve does not need to wrap at the end of variable plus end = "": 
  

  example: 

 
 from __future__ import print_function 

  x='a' 

  y='b' 

  print(x,end='') 

  print (y) 

  Interactive Programming 

  Command prompt, type "Python" command to start the Python interpreter: 

  $ python3 

  Scripted Programming 

  The following command to execute the script: 

  python3 hello.py 

 
 import 与 from...import 

  In the python with the import or to import from ... import corresponding module. 

  The entire module (somemodule) introducing the format: import somemodule 

  Import a function from a module, the format is: from somemodule import somefunction 

  从某个模块中导入多个函数,格式为： from somemodule import firstfunc, secondfunc, thirdfunc 

  将某个模块中的全部函数导入，格式为： from somemodule import * 

  import sys 

  print('命令行参数') 

  for i in sys.argv: 

  print('文件地址：'+i) 

  sys = str(sys.path) # sys.path返回的是列表，强制转换为字符串格式方便输出 

  print('\n路径为 \n' +sys) 