Python程序的输出|第 12 集（列表和元组）

先决条件：列表和元组
注意：所有这些程序的输出都在 Python3 上进行了测试

1) 以下程序的输出是什么？

PYTHON

L1 = []
L1.append([1, [2, 3], 4])
L1.extend([7, 8, 9])
print(L1[0][1][1] + L1[2])

a) 类型错误：只能将列表（不是“int”）连接到列表
b) 12
c) 11
d) 38

Ans: (c) 
Explanation: In the print(), indexing is used. L1[0] denotes [1, [2, 3], 4], L1[0][1] denotes [2, 3], 
L1[0][1][1] = 3 and L1[2] = 8. Thus, the two integers are added, 3 + 8 = 11 and output comes as 11.

2) 以下程序的输出是什么？

PYTHON

L1 = [1, 1.33, 'GFG', 0, 'NO', None, 'G', True]
val1, val2 = 0, ''
for x in L1:
    if(type(x) == int or type(x) == float):
        val1 += x
    elif(type(x) == str):
        val2 += x
    else:
        break
print(val1, val2)

a) 2 GFGNO
b) 2.33 GFGNOG
c) 2.33 GFGNONoneGTrue
d) 2.33 GFGNO

Ans: (d) 
Explanation: val1 will only have integer and floating values val1 = 1 + 1.33 + 0 = 2.33 and val2 will have string
             values val2 ='GFG' + 'NO' = 'GFGNO'. String 'G' will not be part of val2 as the for loop will break at None,
             thus 'G' will not be added to val2.

3) 以下程序的输出是什么？

蟒蛇3

L1 = [1, 2, 3, 4]
L2 = L1
L3 = L1.copy()
L4 = L3
L1[0] = [5]
print(L1, L2, L3, L4)

a) [5, 2, 3, 4] [5, 2, 3, 4] [1, 2, 3, 4] [1, 2, 3, 4]
b) [[5], 2, 3, 4] [[5], 2, 3, 4] [[5], 2, 3, 4] [1, 2, 3, 4]
c) [5, 2, 3, 4] [5, 2, 3, 4] [5, 2, 3, 4] [1, 2, 3, 4]
d) [[5], 2, 3, 4] [[5], 2, 3, 4] [1, 2, 3, 4] [1, 2, 3, 4]

Ans: (d) 
Explanation: L2 is the reference pointing to the same object as L1,
             while L3 and L4 are single recursive Copy(Shallow Copy) of List L1.
             L1[0] = [5], implies that at index 0, list [5] will be present and not integer value 5.

4) 以下程序的输出是什么？

PYTHON

import sys
L1 = tuple()
print(sys.getsizeof(L1), end = " ")
L1 = (1, 2)
print(sys.getsizeof(L1), end = " ")
L1 = (1, 3, (4, 5))
print(sys.getsizeof(L1), end = " ")
L1 = (1, 2, 3, 4, 5, [3, 4], 'p', '8', 9.777, (1, 3))
print(sys.getsizeof(L1))

a) 0 2 3 10
b) 32 34 35 42
c) 48 64 72 128
d) 48 144 192 480

Ans: (c) 
Explanation: An Empty Tuple has 48 Bytes as Overhead size and each additional element requires 8 Bytes. 
(1, 2) Size: 48 + 2 * 8 = 64 
(1, 3, (4, 5)) Size: 48 + 3 * 8 = 72 
(1, 2, 3, 4, 5, [3, 4], 'p', '8', 9.777, (1, 3)) Size: 48 + 10 * 8 = 128 

5) 以下程序的输出是什么？

PYTHON

T1 = (1)
T2 = (3, 4)
T1 += 5
print(T1)
print(T1 + T2)

a) 类型错误
b) (1, 5, 3, 4)
c) 1 个类型错误
d) 6 类型错误

Ans: (d) 
Explanation: T1 is an integer while T2 is tuple. Thus T1 will become 1 + 5 = 6. But an integer and tuple cannot be added, it will throw TypeError.