流程控制主while,for,python画金字塔，画9*9乘法表
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_time: ←--- |
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)*'*')
