Python---day4作业

1.打印 9 * 9乘法表：
格式：
1 * 1 = 1
2 * 1 = 2 2 * 2 = 4
3 * 1 = 3 3 * 2 = 6 3 * 3 = 9
…
9 * 1 = 9 9 * 2 = 18 … 9 * 9 = 81

1. 使用for循环来实现(嵌套循环)

for i in range(1, 10):
     for j in range(1, i + 1):
         print(i, "*", j, "=", i * j, end="t")
     print(" ")

1 * 1 = 1	 
2 * 1 = 2	2 * 2 = 4	 
3 * 1 = 3	3 * 2 = 6	3 * 3 = 9	 
4 * 1 = 4	4 * 2 = 8	4 * 3 = 12	4 * 4 = 16	 
5 * 1 = 5	5 * 2 = 10	5 * 3 = 15	5 * 4 = 20	5 * 5 = 25	 
6 * 1 = 6	6 * 2 = 12	6 * 3 = 18	6 * 4 = 24	6 * 5 = 30	6 * 6 = 36	 
7 * 1 = 7	7 * 2 = 14	7 * 3 = 21	7 * 4 = 28	7 * 5 = 35	7 * 6 = 42	7 * 7 = 49	 
8 * 1 = 8	8 * 2 = 16	8 * 3 = 24	8 * 4 = 32	8 * 5 = 40	8 * 6 = 48	8 * 7 = 56	8 * 8 = 64	 
9 * 1 = 9	9 * 2 = 18	9 * 3 = 27	9 * 4 = 36	9 * 5 = 45	9 * 6 = 54	9 * 7 = 63	9 * 8 = 72	9 * 9 = 81

2. 使用while循环来实现(嵌套循环)

i = 1
while i < 10:
    j = 1
    while j <= i:
        print(i , "*", j, "=", i * j, end="t")
        j = j + 1
    i = i + 1
    print()

1 * 1 = 1	
2 * 1 = 2	2 * 2 = 4	
3 * 1 = 3	3 * 2 = 6	3 * 3 = 9	
4 * 1 = 4	4 * 2 = 8	4 * 3 = 12	4 * 4 = 16	
5 * 1 = 5	5 * 2 = 10	5 * 3 = 15	5 * 4 = 20	5 * 5 = 25	
6 * 1 = 6	6 * 2 = 12	6 * 3 = 18	6 * 4 = 24	6 * 5 = 30	6 * 6 = 36	
7 * 1 = 7	7 * 2 = 14	7 * 3 = 21	7 * 4 = 28	7 * 5 = 35	7 * 6 = 42	7 * 7 = 49	
8 * 1 = 8	8 * 2 = 16	8 * 3 = 24	8 * 4 = 32	8 * 5 = 40	8 * 6 = 48	8 * 7 = 56	8 * 8 = 64	
9 * 1 = 9	9 * 2 = 18	9 * 3 = 27	9 * 4 = 36	9 * 5 = 45	9 * 6 = 54	9 * 7 = 63	9 * 8 = 72	9 * 9 = 81

3. 扩展: 使用单层循环(一层循环)

i = 1
j = 1
while i <= 9:
    if j <= i:
        print(i, "*", j, "=", i * j, end="t")
        j +=1
    else:
        print()
        i +=1
        j = 1

1 * 1 = 1	
2 * 1 = 2	2 * 2 = 4	
3 * 1 = 3	3 * 2 = 6	3 * 3 = 9	
4 * 1 = 4	4 * 2 = 8	4 * 3 = 12	4 * 4 = 16	
5 * 1 = 5	5 * 2 = 10	5 * 3 = 15	5 * 4 = 20	5 * 5 = 25	
6 * 1 = 6	6 * 2 = 12	6 * 3 = 18	6 * 4 = 24	6 * 5 = 30	6 * 6 = 36	
7 * 1 = 7	7 * 2 = 14	7 * 3 = 21	7 * 4 = 28	7 * 5 = 35	7 * 6 = 42	7 * 7 = 49	
8 * 1 = 8	8 * 2 = 16	8 * 3 = 24	8 * 4 = 32	8 * 5 = 40	8 * 6 = 48	8 * 7 = 56	8 * 8 = 64	
9 * 1 = 9	9 * 2 = 18	9 * 3 = 27	9 * 4 = 36	9 * 5 = 45	9 * 6 = 54	9 * 7 = 63	9 * 8 = 72	9 * 9 = 81

2.异常处理的使用：

列表超出索引: list_data = [1, 2, 3] => list_data[3]

try:
    list_data = [1, 2, 3]
    print(list_data[3])
except IndexError:
    print("Error")

Error

定义一个元组: tuple_data = (1, 2, 3) => tuple_data[2] = 10

try:
   tuple_data = (1, 2, 3)
   tuple_data[2] = 10
except TypeError:
   print("typeerror")

typeerror

定义一个字典：dict_data = {1: 2, 2: 3} => dict_data[3]

try:
    dict_data = {1:2, 2:3}
    print(dict_data[3])
except KeyError:
    print("keyerror")

keyerror

3.文件操作：
a.写文本文件：
一次写入多行内容
关闭文件
重新打开，往文件追加新的一行内容

file_obj = open("file1", "w", encoding="utf-8")
file_obj.write("n".join(["爱奇艺", "芒果", "优酷", "腾讯n"]))
file_obj.close()
file_obj = open("file1", "a", encoding="utf-8")
file_obj.write("各大影视软件")
file_obj.close()

爱奇艺
芒果
优酷
腾讯
各大影视软件

b.读文件：
读取前三十字符所在的行

file_obj = open("file2", "w", encoding="utf-8")
file_obj.write("n".join(["今天是星期天", "天气阴", "有点冷", "大家多穿衣注意保暖",  "2021年10月23日"]))
file_obj = open("file2", encoding="utf-8")
data = file_obj.readlines(30)
print(data)

['今天是星期天n', '天气阴n', '有点冷n', '大家多穿衣注意保暖n', '2021年10月23日']

Python---day4作业

Python相关栏目本月热门文章