0 ⽬标
⼀. 列表推导式
# 1. 准备⼀个空列表 list1 = [] # 2. 书写循环,依次追加数字到空列表list1中 i = 0 while i < 10: list1.append(i) i += 1 print(list1)
list1 = [] for i in range(10): list1.append(i) print(list1)
list1 = [i for i in range(10)] print(list1)
list1 = [i for i in range(0, 10, 2)] print(list1)
list1 = [i for i in range(10) if i % 2 == 0] print(list1)
[(1, 0), (1, 1), (1, 2), (2, 0), (2, 1), (2, 2)]
list1 = [(i, j) for i in range(1, 3) for j in range(3)] print(list1)
⼆. 字典推导式
list1 = ['name', 'age', 'gender'] list2 = ['Tom', 20, 'man']
dict1 = {i: i**2 for i in range(1, 5)} print(dict1) # {1: 1, 2: 4, 3: 9, 4: 16}
list1 = ['name', 'age', 'gender'] list2 = ['Tom', 20, 'man'] dict1 = {list1[i]: list2[i] for i in range(len(list1))} print(dict1)
counts = {'MBP': 268, 'HP': 125, 'DELL': 201, 'Lenovo': 199, 'acer': 99} # 需求:提取上述电脑数量⼤于等于200的字典数据 count1 = {key: value for key, value in counts.items() if value >= 200} print(count1) # {'MBP': 268, 'DELL': 201}
三. 集合推导式
list1 = [1, 1, 2]
list1 = [1, 1, 2] set1 = {i ** 2 for i in list1} print(set1) # {1, 4}
四. 总结
# 列表推导式 [xx for xx in range()] # 字典推导式 {xx1: xx2 for ... in ...} # 集合推导式 {xx for xx in ...}