相关推导式-Python

列表、’字典等推导式

 #利用zip()函数同时给多个变量赋值
 a = [1,2,3,4,5]
 b = [4,5,6,7,8]
 c = [9,2,3,4,0]
 l = [[1,2],[3,4]]
 for x,y,z in zip(a,b,c):
     print(x,y,z)

 #利用推导式来找符合条件的两个列表中的元素
 d = [i for i in a if i not in b]
 print(d)
 #if not为假的时候执行,与if相反
 e = [j+1 if not j%2 else j-1 for j in a]
 print(e)
 #两个for的推导式
 f = [(i,j) for i in a if i%2 for j in b if j>5]
 print(f)
 g = [x for y in l for x in y]
 print(g)
 #遍历字典
 list1 = [('HW','华为'),('ZTE','中兴'),('MI','小米'),('CISCO','思科')]
 dict1 = {key:value for key,value in list1}
 print(dict1)
 #将字典键和值对调
 dict2 = {'k1':'','k2':'','k3':''}
 new_dict2 = {value:key for key,value in dict2.items()}
 print(new_dict2)