day13列表推导式作业详解

1.day13题目

2，用列表推导式做下列小题

(1)过滤掉长度小于3的字符串列表，并将剩下的转换成大写字母

(2)求(x,y)其中x是0-5之间的偶数，y是0-5之间的奇数组成的元祖列表

(3)求M中3,6,9组成的列表M = [[1,2,3],[4,5,6],[7,8,9]]

(4)求出50以内能被3整除的数的平方，并放入到一个列表中。

(5)构建一个列表：['python1期', 'python2期', 'python3期', 'python4期', 'python6期', 'python7期', 'python8期', 'python9期', 'python10期']

(6)构建一个列表：[(0, 1), (1, 2), (2, 3), (3, 4), (4, 5), (5, 6)]

(7)构建一个列表：[0, 2, 4, 6, 8, 10, 12, 14, 16, 18]

(8)有一个列表l1 = ['alex', 'WuSir', '老男孩', '太白']将其构造成这种列表['alex0', 'WuSir1', '老男孩2', '太白3']

(9)有以下数据类型：

x = {
    'name':'alex',
    'Values':[{'timestamp':1517991992.94,
         'values':100,},
        {'timestamp': 1517992000.94,
        'values': 200,},
        {'timestamp': 1517992014.94,
         'values': 300,},
        {'timestamp': 1517992744.94,
         'values': 350},
        {'timestamp': 1517992800.94,
         'values': 280}
		],}

将上面的数据通过列表推导式转换成下面的类型：

[[1517991992.94, 100], [1517992000.94, 200], [1517992014.94, 300], [1517992744.94, 350], [1517992800.94, 280]]

2.题目详解

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2-1
lst = ['Alex','Jack','Anna','Jason','Pako','aj']
ll = [i.upper() for i in lst if len(i)>3]
print(ll)

2-2

lst = [(i,j) for i in range(5) if i%20 for j in range(5)  if j%21]

print(lst)

lst = [(i,j) for i in range(0,5,2) for j in range(1,5,2)]

print(lst)

2-3

M = [[1,2,3],[4,5,6],[7,8,9]]

lst = [i[2] for i in M]

print(lst)

M = [[i-2,i-1,i] for i in [3,6,9]]

print(M)

2-4

lst = [i**2 for i in range(51) if i%3==0]

print(lst)

2-5

lst = ['python%s期'%i for i in range(1,11)]

print(lst)

2-6

lst = [(i,el) for i,el in enumerate(range(1,7))]

print(lst)

lst = [(i,i+1) for i in range(6)]

print(lst)

2-7

lst = [i for i in range(0,20,2)]

print(lst)

2-8

l1 = ['alex', 'WuSir', '老男孩', '太白']

new_lst = ['%s%s'%(el,i) for i,el in enumerate(l1)]

print(new_lst)

2-9

x={

'name':'alex',

'Values':[{'timestamp':1517991992.94,'values':100},

{'timestamp':1517992000.94,'values':200},

{'timestamp':1517992014.94,'values':300},

{'timestamp':1517992744.94,'values':350},

{'timestamp':1517992800.94,'values':280},

]}

lst = [[i['timestamp'],i['values']] for i in x['Values']]

print(lst)