【每日一练】python列表

1、输入一个整数列表，将列表中的元素按照逆序输出。

list1=[5,4,5,6]
list1.reverse()
print(list1)

[6, 5, 4, 5]

2、输入一个字符串列表，输出其中长度大于等于5的字符串，并且将它们转换为大写形式。

list1=['hello','lol','ak47','aliang']
for i in list1:if len(i) >=5:print(i.upper())

HELLO
ALIANG

3、输入一个整数列表，输出该列表中所有奇数的平方和。

list1=[1,2,3,4,5,6,7,8,9]
sum = 0
for num in list1:if num % 2 == 1:sum += num ** 2
print(sum)

165

4、输入一个列表，输出该列表中所有正整数的和。

list1=[-5,-1,0,1,2,3,1.7,'i']
sum = 0
for num in list1:if isinstance(num, (int)) and num > 0 :sum+= num
print(sum)

6

5、输入一个列表，输出该列表中所有偶数的平均值。

list1=[-5,-1,0,1,2,3,1.7,'i']
sum = 0
i = 0
for num in list1:if isinstance(num, (int)) and num % 2 == 0 :sum+= numi+=1
print(sum/i)

1.0

6、已知一个数字列表，求所有元素和。

lst = [51, 54, 85, 45, 80, 45, 12, 96, 789, 45, 69]

lst = [51, 54, 85, 45, 80, 45, 12, 96, 789, 45, 69]
sum = 0
for numb in lst:sum += numb
print(sum)

1371

7、已知一个数字列表，输出所有奇数下标元素。

lst = [59, 54, 89, 45, 78, 45, 12, 96, 789, 45, 69]

lst = [59, 54, 89, 45, 78, 45, 12, 96, 789, 45, 69]
for j in range(len(lst)):if j % 2 == 1:print(lst[j])

54
45
45
96
45

8、已知一个数字列表，输出所有元素中，值为奇数的元素。

lst = [59, 54, 89, 45, 78, 45, 12, 96, 789, 45, 69]

lst = [59, 54, 89, 45, 78, 45, 12, 96, 789, 45, 69]
for i in lst:if i % 2 == 1:print(i)

59
89
45
45
789
45
69

9、已知一个数字列表，将所有元素乘二。

nums = [1, 2, 3, 4]

nums = [1, 2, 3, 4]
for j in range(len(nums)):nums[j] = nums[j] * 2
print(nums)

[2, 4, 6, 8]

10、有一个长度是10的列表，数组内有10个人名，要求去掉重复的

例如:names = [‘张三’, ‘李四’, ‘大黄’, ‘张三’] -> names = [‘张三’, ‘李四’, ‘大黄’]

names = ['张三', '李四', '大黄', '张三','小黑','小白','小明','小红']

names = ['张三', '李四', '大黄', '张三', '小黑', '小白', '小明', '小红']
names_unique = []
for name in names:if name not in names_unique:names_unique.append(name)print(names_unique)

['张三', '李四', '大黄', '小黑', '小白', '小明', '小红']

11、有一个数字列表，获取这个列表中的最大值.(注意: 不能使用max函数)

nums = [19, 89, 90, 600, 1]

nums = [19, 89, 90, 600, 1]
max_nums = 0
for i in nums:if i > max_nums:max_nums = i
print(max_nums)

600

12、用一个列表来保存一个节目的所有分数，求平均分数(去掉一个最高分，去掉一个最低分，求最后得分)

scores = [9.8, 9.5, 9.9, 9.3, 8.9, 9.5, 9.6, 9.3, 9.4, 9.6]

scores = [9.8, 9.5, 9.9, 9.3, 8.9, 9.5, 9.6, 9.3, 9.4, 9.6]
min_score = 10
min_num = 0
max_score = 0
max_num = 0
for i in range(len(scores)):if scores[i] > max_score:max_score = scores[i]max_num = iif scores[i] < min_score:min_score = scores[i]min_num = i
del scores[min_num]
del scores[max_num]
sum_score = 0
for score in scores:sum_score += score
avg_score = sum_score / len(scores)
print(avg_score)

9.5

scores = [9.8, 9.5, 9.9, 9.3, 8.9, 9.5, 9.6, 9.3, 9.4, 9.6]# 对分数列表进行排序
scores.sort()# 去掉一个最高分和一个最低分
scores = scores[1:-1]sum_score = 0
for score in scores:sum_score += score
avg_score = sum_score / len(scores)
print(avg_score)

9.5

scores = [9.8, 9.5, 9.9, 9.3, 8.9, 9.5, 9.6, 9.3, 9.4, 9.6]
scores.remove(max(scores))
scores.remove(min(scores))
score = sum(scores) / len(scores)
print(score)

9.5

13、有两个列表A和B，使用列表C来获取两个列表中公共的元素

例如: A = [1, ‘a’, 4, 90] B = [‘a’, 8, ‘j’, 1] --> C = [1, ‘a’]

A = [1, 'a', 4, 90]
B = ['a', 8, 'j', 1]
C = []
for i in A:if i in B:C.append(i)
print(C) 

[1, 'a']

14、获取列表中出现次数最多的元素

nums = [1, 2, 3,1,4,2,1,3,7,3,3]

nums = [1, 2, 3,1,4,2,1,3,7,3,3]
res = 0
res_i = 0
for i in nums:if nums.count(i) > res:res = nums.count(i)res_i = i
print(res_i)

3

15、将scores中所有的及格的分数提取出来

scores = [89, 67, 56, 90, 98, 30, 78, 51, 99]

scores = [89, 67, 56, 90, 98, 30, 78, 51, 99]
scores_pass = []
for score in scores:if score >= 60:scores_pass.append(score)
print(scores_pass)

[89, 67, 90, 98, 78, 99]

16、输入一个整数列表，输出其中最大的两个元素的乘积。

lst=[2,6,7,10,3,5,4,9,8]
lst.sort(reverse=True)
print(lst[0]*lst[1])

90

17、已知一个数字列表，求所有元素的平均数

lst = [59, 54, 89, 45, 78, 45, 12, 96, 789, 45, 69]

lst = [59, 54, 89, 45, 78, 45, 12, 96, 789, 45, 69]
sum_score = 0
for score in lst:sum_score += score
avg_score = sum_score / len(lst)
print(avg_score)

125.54545454545455

18、输入一个字符串列表，输出其中最长的字符串。

lst = ['apple', 'banana', 'pear', 'orange', 'kiwi', 'mango']

lst = ['apple', 'banana', 'pear', 'orange', 'kiwi', 'mango']
res = []
num = 0
for k in lst:if len(k) > num:num = len(k)res = [k]elif len(k) == num:res.append(k)
print(res)

['banana', 'orange']

19、输入一个字符串列表，输出其中第一个字母是元音字母的单词（不区分大小写）。

lst = ['apple', 'Banana', 'pear', 'Orange', 'kiwi', 'mango']

lst = ['apple', 'Banana', 'pear', 'Orange', 'kiwi', 'mango']
vowels = ['a','e','i','o','u','A','E','I','O','U']
for fruit in lst:for char in vowels:if fruit.startswith(char):print(fruit)

apple
Orange

20、已有两个列表，输出它们的笛卡尔积。

lst1 = [1, 2, 3]
lst2 = ['a', 'b','c']

lst1 = [1, 2, 3]
lst2 = ['a', 'b','c']
for i in lst1:for j in lst2:print(i, j)

1 a
1 b
1 c
2 a
2 b
2 c
3 a
3 b
3 c