python练习题2

1.将下面列表中各个元素的第二个字符取出来并且按顺序排列

word = [‘abc’,‘blibli’,‘DNA’,‘Aoe’,‘Cent’,‘ed’]

word = ['abc','blibli','DNA','Aoe','Cent','ed']
list = []
for i in word:
    list.append(i[1])
list.sort()
print(list)

2.输入一个精度为0.01的浮点数,根据四舍五入保存它的值,使其精度为0.1

a = float(input("请输入一个精度为0.01的浮点数："))
if a*100%10 >= 5:
    a = int(a*10+1)/10
else:
    a = int(a*10)/10
print(a)

3.任意输入一个整数,打印出从它本身一直到零的每个数

如果输入浮点数会报错,并提示重新输入

def number():
    for i in range(1):
        try:
            a = int(input("请输入一个整数："))
            if a > 0:
                while a != -1:
                    print(a)
                    a -= 1
            elif a < 0:
                while a != 1:
                    print(a)
                    a += 1
            elif a == 0:
                print(a)
        except Exception as e:
            print("你输入的不是一个整数，请重新输入：")
            print("===========================")
            number()
        break
number()

4.根据第一题列表中元素中的第二个字符,有序排列列表

不用考虑第二个字符一样的情况

lis = ['abc','blibli','DNA','Aoe','Cent','ed']
for i in lis:
    for j in range(5):
        if lis[j][1] > lis[j+1][1]:
            sum = lis[j]
            lis[j] = lis[j+1]
            lis[j+1] = sum
print(lis)