程序猿面试题集锦

1、列表解析、lambda 匿名函数

value = [lambda: x + 100 for x in range(10)]
print(value[0])
print(value[0]())
>>:
    <function <listcomp>.<lambda> at 0x0000021FBB52D9D8>
    109
      
# 扩展
def multipliters():
    """
     for i in range(4): 循环4次，最终i=3
    :return:[lambda x: i * x, lambda x: i * x, lambda x: i * x, lambda x: i * x]
    """
    return [lambda x: i * x for i in range(4)]

print([m(2) for m in multipliters()])

>>：
    [6, 6, 6, 6]

　　

2、函数默认参数

默认参数为可变类型：

def bar(lt1,lt2 = []):
    lt2.append(lt1)
    return lt2

l1 = bar(1,[3,4])
print(id(l1),l1)

l2 = bar(1)
print(id(l2),l2)

l3 = bar(2,[3,4])
print(id(l1),l3)

l4 = bar(2)
print(id(l4),l4)

>>:
   2542419966728 [3, 4, 1]
   2542419946120 [1]
   2542419966728 [3, 4, 2]
   2542419946120 [1, 2]

默认参数为不可变类型：

def foo(tp1,tp2=()):
    return tp1+tp2

t1 = foo((1,),(3,4))
print(id(t1),t1)

t2 = foo((1,))
print(id(t2),t2)

t3 = foo((2,),(3,4,5))
print(id(t3),t3)

t4 = foo((2,))
print(id(t4),t4)

'''
2874698184384 (1, 3, 4)
2874698241584 (1,)
2874698161992 (2, 3, 4, 5)
2874698241528 (2,)

'''

默认参数为不可变类型