Python Learning Notes (vi) Python first program

Python statement

Assignment statements

1. Assign the 3 object to the variable a

2, 3, 4 is assigned to the variable, a, b

1 >>> a = 3       2 >>> A, B = 3,43 >>> a4 35 >>> b6 47 >>> a = 3,48 >>> a9 (3, 4)

3, the realization will a,b=3,4 exchange a,b=4,3

1>>> b =3,4 Generally we declare a temporary variable to resolve2>>> temp =a3>>> A =b4>>> B =Temp5>>>a647>>>b839>>> b,a=This can be done in Python, because the variable has no type and the object has a typeTen>>>a One3 A>>>b -4 ->>>

4. First program Hello Word

Ⅰ Create a new py file helloword.py with the following

Print " Hellword "

Execute at command line (CMD)

1 g:\pythonworkspace>2 g:\pythonworkspace>python helloword.py3 Hellword

Ⅱ Four operator creates a new file study.py with the contents of

① The first behavior is used to specify the interpreter that executes the script, telling the computer that the program executes the name of the system variable

② second behavior encoding format set to UTF-8

③ third line three double or three single quotation marks for document comments

  1  #  !/ Usr/bin/env python   2  #  coding:utf-8   3   4  Span style= "COLOR: #800000" "" ""   5   calculation   6  56+8*5-18/9   7    8   9  A = 8 * 5-18/9 #   arithmetic  
    
     10 
     print  a 

1 g:\pythonworkspace>python study.py    command line execution 2 94

　　

Python Learning Notes (vi) Python first program