1.for循环的使用,注意下面代码的区别
for i in range(0,10,2): print("i love you")
for i in range(0,10): print("i love you")
for i in range(5): print("i love you")
2.break与continue的区别
for i in range(5): if i == 2: break print(i)
for i in range(5): if i == 2: continue print(i)
break是执行到i==2时,跳出整个循环,continue是跳出i==2这个循环。
while True: while True: break #跳出的是第二个while,但还是要打印2 print(1) print(2) break #跳出的是第一个while,但还是要打印3 print(3)
3.我爱你的长度
i = 0 string = "i love you" while i < len(string): print(i) i += 1
改进版:
i = 0 string = "i love you" length = len(sring) while i < length: print(i) i += 1
改进原因:每次循环都要调用len()函数
4.
answer = 'i love you' times = 3 while times: times -= 1 key = str(input('请输入密码:')) if key == answer: print('密码正确,进入程序....') break elif "*" in key: print('密码中不能含有"*"号!您还有3次机会!',end = ' ') continue elif times == 0: print('账号已被绑定,请等待十分钟!!!') else: print('密码输入错误!你还有',times,'次机会!',end = ' ')
另附小甲鱼的源代码:
count = 3 password = 'FishC.com' while count: passwd = input('请输入密码:') if passwd == password: print('密码正确,进入程序......') break elif '*' in passwd: print('密码中不能含有"*"号!您还有', count, '次机会!', end=' ') continue else: print('密码输入错误!您还有', count-1, '次机会!', end=' ') count -= 1
5.求水仙花数
for i in range(100,1000): result = 0 #给变量起名时,尽量注意不要使用内置函数 temp = i while temp: result = result + (temp%10)**3 #temp是随着下面的公式变化的 temp //= 10 #地板除的使用 if result = i: #判断幂的和等于数值的大小 print(i)
另附小甲鱼源代码:
for i in range(100, 1000): sum = 0 temp = i while temp: sum = sum + (temp%10) ** 3 temp //= 10 # 注意这里要使用地板除哦~ if sum == i: print(i)
6.乒乓球的分配(3个红色,3个黄色,6个绿色,随机取出8个,一共多少种结果)看小甲鱼的,自己不会写:
print('red\tyellow\tgreen') for red in range(0,4): for yellow in range(0,4): for green in range(2,7): #绿色必须有两个 if red + yellow + green = 8: print(red,'\t',yellow,'\t',green,'\t')
注释代码:
for i in range(0,4): print(i)
for i in range(2,7): print(i)
SB的全称是smart boy