5.6 自我总结

一.流程控制while

1.while

while True: #while + 条件满足进行下面的循环

age = input('age:') #while 循环的内容

2.while...break

while True: #while + 条件满足进行下面的循环

age = input('age:') #while 循环的内容

break #停止本次循环

补充

a = True#循环语是子上而下的，当While中条件不满足时也会停止while下面内容的循环

while a == True:

age = input('age:')

if type(age) == type('1'):

a = False

3.while...continue

num = 0

num_time = 3

while num

num +=1 |

if num == 1: |

continue--------- #相当于如果NUM的值等于1时候不进行下面的运算，但是不跳出While，返回while print(num)

4.while...else

n = 1

while n < 3:

print(n)

n += 1

else:

print('else会在while没有被break时才会执行else中的代码')

5.while的嵌套

例如

while True:

user_db = 'nick'

pwd_db = '123'

inp_user = input('username: ')

inp_pwd = input('password: ')

if inp_user == user_db and pwd_db == inp_pwd:

print('login successful')

while True:

cmd = input('请输入你需要的命令：')

if cmd == 'q':

break

print(f'{cmd} 功能执行')

else:

print('username or password error')

print('退出了while循环')

二.流程控制for(和while用法差不多)

1.for

2.for...break

3.for...continue

4.for...else

5.for的嵌套

三.for与while的区别

for和while条件者快一个是可控的一个是不可控的，while容易出现死循环

四.今日题目

1. 打印1-100之间的偶数：

```python

for num in range(100):

num += 1

if num % 2 == 1:

continue

print(num)

```

​

2.猜年龄游戏升级版，有以下三点要求

允许用户最多尝试3次

每尝试3次后，如果还没猜对，就问用户是否还想继续玩，如果回答Y或y， 就继续让其猜3次，以此往复，如果回答N或n，就退出程序

如何猜对了，就直接退出

```python

#允许最多输入三次年龄

#三次没有猜对让用户输入Yory表示继续，Norn表示退出

#猜对直接退出

time = 0

ipt_time = 3

while time < ipt_time+1:

age =input('请输入您的年龄：')

age =int(age)

if age ==18:

print('恭喜你猜对了')

break

elif age < 18:

print('小了，请再试试')

else:

print('大了，请再试试')

time += 1

if time == 3:

print('你想不想再玩')

choose = input(f'(输入Y或y继续玩，输入N或n不想玩退出)')

if choose =='Y'or choose == 'y':

time = 0

elif choose == 'N' or choose == 'n':

time = 4

else:

print('不听话乱输入\n请好好输入')

```

3.99乘法表

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

#第一种

for row_1 in range(1):

print(f'1*{row_1+1}')

for row_2 in range(2):

print(f'2*{row_2+1} ',end='')

for row_3 in range(3):

if row_3 == 0:

print(end='\n'f'3*{row_3+1} ')

continue

print(f'3*{row_3+1} ',end='')

for row_4 in range(4):

if row_4 == 0:

print(end='\n'f'4*{row_4+1} ')

continue

print(f'4*{row_4+1} ',end='')

for row_5 in range(5):

if row_5 == 0:

print(end='\n'f'5*{row_5+1} ')

continue

print(f'5*{row_5+1} ',end='')

for row_6 in range(6):

if row_6 == 0:

print(end='\n'f'6*{row_6+1} ')

continue

print(f'6*{row_6+1} ',end='')

for row_7 in range(7):

if row_7 == 0:

print(end='\n'f'7*{row_7+1} ')

continue

print(f'7*{row_7+1} ',end='')

for row_8 in range(8):

if row_8 == 0:

print(end='\n'f'8*{row_8+1} ')

continue

print(f'8*{row_8+1} ',end='')

for row_9 in range(9):

if row_9 == 0:

print(end='\n'f'9*{row_9+1} ')

continue

print(f'9*{row_9 + 1} ', end='')

#第二种改进

for num_former in range(1,10):

for num_latter in range (1,num_former+1):

if num_former ==num_latter:

print(f'{num_former}*{num_latter} ')

continue

print(f'{num_former}*{num_latter} ',end='')

#居然漏了下面结果(一直在想优化了)

for num_former in range(1,10):

for num_latter in range (1,num_former+1):

if num_former ==num_latter:

print(f'{num_former}*{num_latter}={num_former*num_latter} ')

continue

print(f'{num_former}*{num_latter}={num_former*num_latter} ',end='')

4.打印如下所示金字塔

# max_level=5

* # current_level=1，空格数=4，*号数=1 1

*** # current_level=2，空格数=3，*号数=3 3

***** # current_level=3，空格数=2，*号数=5 5

******* # current_level=4，空格数=1，*号数=7

********* # current_level=5，空格数=0，*号数=9

# 数学表达式

空格数 = max_level-current_level

*号数 = 2*current_level-1

'''

#方法1

print(f' *')

print(f' ***')

print(f' *****')

print(f' *******')

print(f'*********')

#方法二

for row_1 in range(6):

if row_1 == 0:

print(' ')

elif row_1 == 1:

print(f' *')

elif row_1 == 2:

print(f' ***')

elif row_1 == 3:

print(f' *****')

elif row_1 == 4:

print(f' *******')

elif row_1 == 5:

print(f'*********')

#方法三

# max_level=5

* # current_level=1，空格数=4，*号数=1 1 = 0+1

*** # current_level=2，空格数=3，*号数=3 3 = 1+2

***** # current_level=3，空格数=2，*号数=5 5 = 2+3

******* # current_level=4，空格数=1，*号数=7 7 = 3+4

********* # current_level=5，空格数=0，*号数=9 9 = 4+5

for row in range(6):

A = (5-row)*' '

B = (2*row+1)*'*'

print(f"{A}{B}")

#再精简

for row in range(6):

print((5-row)*' '+(2*row+1)*'*')

#漏了开头一行，

print('')

for row in range(6):

print((5-row)*' '+(2*row+1)*'*')

#或者

for row in range(7):

if row == 0:

print('')

continue

print((5-(row-1))*' '+(2*(row-1)+1)*'*')