Python基础之Python语句

Python语句

赋值语句

  >>> (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'))

条件语句

  
  score = 75
  if score >= 90:
      print('优秀')
  elif score >= 80:
      print('良好')
  elif score >= 60:
      print('及格')
  else:
      print('不及格')
      

  
  def add(x):
      print(x + 10)
  ​
  operation = {
      'add': add,
      'update': lambda x: print(x * 2),
      'delete': lambda x: print(x * 3)
  }
  ​
  operation.get('add')(10)
  operation.get('update')(10)
  operation.get('delete')(10)
  ​
  #三元表达式
  result = '及格' if score >= 60 else '不及格'

循环语句