分支循环相关

分支:

1.判断今天是今年第几天

# __author__ = "wyb"
# date: 2018/3/18
# 判断今天是今年第几天
import time


def demo(year, month, day):
    day_month = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
    if year % 400 == 0 or (year % 4 == 0 and year % 100 != 0):
        day_month[1] = 29
    if month == 1:
        return day
    else:
        return sum(day_month[:month - 1]) + day


date = time.localtime()
y, m, d = date[:3]
print(demo(y, m, d))

2.猜年龄

普通版: 允许用户最多尝试3次，3次都没猜到的话就直接退出，如果猜对了，打印恭喜信息并退出

age = 21
count = 0
while count < 3:
    guess_age = int(input("age is: ").strip())
    if guess_age == age:
        print("恭喜你猜对了!")
        break
    elif guess_age < age:
        print("小了")
    elif guess_age > age:
        print("大了")
    count += 1
else:
    print("最多可以尝试3次哦!")

升级版: 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继续想玩，回答Y或y继续让其猜3次，回答N或n就退出程序，

如果猜对了就直接欢迎然后退出

age = 21
count = 0
while count < 3:
    guess_age = int(input("age is: ").strip())
    if guess_age == age:
        print("恭喜你猜对了!")
        break
    elif guess_age < age:
        print("小了")
    elif guess_age > age:
        print("大了")
    count += 1
    if count == 3:
        choice = input("是否还想继续猜?(输入y继续,输入其他退出): ")
        if choice == 'Y' or choice == 'y':
            count = 0

3.判断闰年

# 满足下面两个条件之一的就是闰年:
# (1)能被4整除但不能被100整除 (2)能被400整除

输入年份判断是否是闰年

# __author__ = "wyb"
# date: 2018/4/14

year = int(input("Input year: ").strip())

if year % 4 == 0 and year%100!=0:
    print("是闰年")
elif year % 400 == 0:
    print("是闰年")
else:
    print("不是闰年")

循环:

1.任意输入三个英文单词，按字典顺序输出

# __author__ = "wyb"
# date: 2018/3/10

# 任意输入三个英文单词，按字典顺序输出

# 方法1:
# s = input('x,y,z=')
# x, y, z = s.split(',')
# if x > y:
#     x, y = y, x
# if x > z:
#     x, z = z, x
# if y > z:
#     y, z = z, y
# print(x, y, z)

# 方法2:
s = input('x,y,z=')
x, y, z = s.split(',')
x, y, z = sorted([x, y, z])
print(x, y, z)

2.给一个不超出5位的正整数，判断有几位，并依次打印个位、十位、百位、千位、万位

# __author__ = "wyb"
# date: 2018/2/21
# (1)给一个不超出5位的正整数，判断有几位，并依次打印个位、十位、百位、千位、万位:
# (2)还有没有更好的打印方法? 如果需求是从万位到个位打印呢?

# (1):
# n = int(input(">>>"))
# print(n)
# i = 0       # 计数
# while n:
#     print(n % 10)
#     n = n//10           # 地板除法(类C语言) -> 5/2 == 2
#     i += 1
#
# print(i)

# (2): 循环:
# n = int(input(">>>"))
# print(n)
# # 确定位数:
# if n >= 1000:
#     if n >= 10000:
#         num = 5
#     else:
#         num = 4列表
# else:
#     if n >= 100:
#         num = 3
#     elif n >= 10:
#         num = 2
#     else:
#         num = 1
# # 从第一位开始输出:
# print(num)
# pre = 0
# for i in range(num, 0, -1):
#     cur = n//(10**(i-1))
#     print(cur - pre*10)
#     pre = cur

# (2): 递归函数:
def func(n):
    if n//10 == 0:
        print(n)
        return
    else:
        func(n//10)
        print(n % 10)

n = int(input(">>>"))
print(n)
func(n)

3.打印以下菱形:

    *
   ***
  *****
 *******
  *****
   ***
    *

# __author__ = "wyb"
# date: 2018/2/25

# 打印以下菱形:
#     *
#    ***
#   *****
#  *******
#   *****
#    ***
#     *

for i in range(-3, 4):
    if i < 0:
        pre_space = -i
    else:
        pre_space = i
    print(" " * pre_space + '*' * (7 - pre_space * 2))

4.打印菱形拓展:

   *
  **
 ***
*******
   ***
   **
   *

# __author__ = "wyb"
# date: 2018/2/25

# 打印以下图形:
#     *
#    **
#   ***
#  *******
#     ***
#     **
#     *

for i in range(-3, 4):
    if i < 0:
        print(" " * (-i) + "*" * (4 + i))
    elif i > 0:
        print(" " * 3 + "*" * (4 - i))
    else:
        print("*" * 7)

5.菲薄纳西数列:(1)打印100以内的菲薄纳西数列(2)求菲薄纳西数列的第101项

# __author__ = "wyb"
# date: 2018/2/21
# (1)打印100以内的菲薄纳西数列
# (2)求菲薄纳西数列的第101项

# (1):
number_first = 1
number_second = 1
while True:
    print(number_first)
    if number_second > 100:
        break
    number_first, number_second = number_second, number_first + number_second

# (2):
number_first = 1
number_second = 1
count = 1
while True:
    if count == 101:
        print(number_first)
    count += 1
    number_first, number_second = number_second, number_first + number_second

6.质数: (1)判断一个数是否是素数(质数)(2)求1万内的素数

# __author__ = "wyb"
# date: 2018/2/21
# (1)判断一个数是否是素数(质数)
# (2)求1万内的素数
# 关于质数: 一个大于1的自然数只能被1和它本身整除

# (1):
# number = int(input(">>>"))
# if number == 2:
#     print("is prime")
# else:
#     for i in range(2, number):
#         if number % i == 0:
#             print("not prime")
#             break
#     else:
#         print("is prime")


# (2):
import time  # 引入模块

count = 1  # 计数
print(2)
start_time = time.time()
for number in range(3, 10000, 2):
    i = 2
    while True:
        i += 1
        if number % i == 0:
            break
        if i * i >= number:
            print(number)
            count += 1
            break
end_time = time.time()
t = end_time - start_time

print("
", count)
print(t)

7.求1到5的阶乘之和: 1! + 2! + 3! + 4! + 5! == 153

# __author__ = "wyb"
# date: 2018/2/21
# 求1到5的阶乘之和: 1! + 2! + 3! + 4列表! + 5!  == 153

# (1)递归函数求阶乘之和:
# def fact(number):
#     if number <= 1:
#         return 1
#     else:
#         return number * fact(number - 1)
#
# sum_fact = fact(1) + fact(2) + fact(3) + fact(4列表) + fact(5)
# print(sum_fact)


# (2)循环求阶乘之和:
num = 1
x = 0
for n in range(1, 6):
    num *= n
    x += num
print(x)

8.打印九九乘法表

# __author__ = 'wyb'
# date: 2018/2/22

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

9.复利计算

问题:  假设一年期定期利率为3.25%，计算一下需要经过多少年，一万元的一年定期存款连本带息能翻番？

# __author__ = "wyb"
# date: 2018/4/14

rate = 0.0325
money = 10000
year = 0
while True:
    year += 1
    money = money*(1+rate)
    print(year)
    print(money)
    if money >= 20000:
        break

print()
print(year)
print(money)

10.求100以内的素数和

# __author__ = "wyb"
# date: 2018/4/15
# 求100以内的素数和

def is_prime(number):
    if number == 2:
        return True
    else:
        for i in range(2, number):
            if number % i == 0:
                return False
        else:
            return True


res = 0
for n in range(2, 100):
    if is_prime(n):
        res += n

print(res)