Python Python basis of statements

Python statements

Assignment

  >>> (x,y) = (5,10)
  >>> x
  5
  >>> y
  10
  >>> x,y = 5,10
  >>> x,y
  (5, 10)
  >>> [x,y,z] = [1,2,3]
  >>> x,y,z
  (1, 2, 3)
  >>> x,y = y,x
  >>> x,y
  (2, 1)
  >>> [a,b,c] = (1,2,3)

  #序列赋值
  >>> a,b,c = 'abc'
  >>> a
  'a'
  >>> b
  'b'
  >>> c
  'c'
  #左右两边不一致
  >>> a,b,*c = 'abcdefgh'
  >>> a
  'a'
  >>> b
  'b'
  >>> c
  ['c', 'd', 'e', 'f', 'g', 'h']
  >>> a,*b,c = 'abcdefgh'
  >>> a
  'a'
  >>> b
  ['b', 'c', 'd', 'e', 'f', 'g']
  >>> c
  'h'
  ​
  >>> s = 'abcderf'
  >>> a,b,c = s[0],s[1],s[2:]
  >>> a
  'a'
  >>> b
  'b'
  >>> c
  'cderf
  ​
  >>> a,b,c,*d = 'abc'
  >>> a
  'a'
  >>> b
  'b'
  >>> c
  'c'
  >>> d
  []
  ​
  ​
  >>> a = b = c = 'hello'
  >>> a
  'hello'
  >>> b
  'hello'

  
  >>> a = 'hello'
  >>> b = 'world'
  >>> print(a,b)
  hello world
  >>> print(a,b,sep='|')
  hello|world
  >>> print(a,b,sep='|',end='...\n')
  hello|world...
  >>> print(a,b,end='...\n',file=open('result.txt','w'))

Conditional statements

  
  = 75 Score 
  IF Score> = 90: 
      Print ( 'excellent') 
  elif Score> = 80: 
      Print ( 'good') 
  elif Score> = 60: 
      Print ( "pass") 
  the else: 
      Print ( 'fail')
      

  
  the Add DEF (X): 
      Print (X + 10) Operation = {     'the Add': the Add,     'Update': the lambda X: Print (X * 2),     'Delete': the lambda X: Print (X *. 3) } operation.get ( 'the Add') (10) operation.get ( 'Update') (10) operation.get ( 'Delete') (10) # ternary expressions with result = 'pass' if score> = 60 else 'fail'
  
  
  
  
  
  
  
  
  
  
  
  
  

loop statement