二、Python流程控制练习题

"""
英制单位英寸和公制单位厘米互换
"""

value = float(input('请输入长度: '))
unit = input('请输入单位: ')
if unit == 'in' or unit == '英寸':
    print('%f英寸 = %f厘米' % (value, value * 2.54))
elif unit == 'cm' or unit == '厘米':
    print('%f厘米 = %f英寸' % (value, value / 2.54))
else:
    print('请输入有效的单位')

"""
掷骰子决定做什么事情
"""

from random import randint

face = randint(1, 6)
if face == 1:
    result = '唱首歌'
elif face == 2:
    result = '跳个舞'
elif face == 3:
    result = '学狗叫'
elif face == 4:
    result = '做俯卧撑'
elif face == 5:
    result = '念绕口令'
else:
    result = '讲冷笑话'
print(result)

"""
百分制成绩转等级制成绩
90分以上    --> A
80分~89分    --> B
70分~79分	   --> C
60分~69分    --> D
60分以下    --> E
"""

score = float(input('请输入成绩: '))
if score >= 90:
    grade = 'A'
elif score >= 80:
    grade = 'B'
elif score >= 70:
    grade = 'C'
elif score >= 60:
    grade = 'D'
else:
    grade = 'E'
print('对应的等级是:', grade)

"""
判断输入的边长能否构成三角形
如果能则计算出三角形的周长和面积
"""

import math

a = float(input('a = '))
b = float(input('b = '))
c = float(input('c = '))
if a + b > c and a + c > b and b + c > a:
    print('周长: %f' % (a + b + c))
    p = (a + b + c) / 2
    area = math.sqrt(p * (p - a) * (p - b) * (p - c))
    print('面积: %f' % (area))
else:
    print('不能构成三角形')

"""
输入月收入和五险一金计算个人所得税
"""

salary = float(input('本月收入: '))
insurance = float(input('五险一金: '))
diff = salary - insurance - 3500
if diff <= 0:
    rate = 0
    deduction = 0
elif diff < 1500:
    rate = 0.03
    deduction = 0
elif diff < 4500:
    rate = 0.1
    deduction = 105
elif diff < 9000:
    rate = 0.2
    deduction = 555
elif diff < 35000:
    rate = 0.25
    deduction = 1005
elif diff < 55000:
    rate = 0.3
    deduction = 2755
elif diff < 80000:
    rate = 0.35
    deduction = 5505
else:
    rate = 0.45
    deduction = 13505
tax = abs(diff * rate - deduction)
print('个人所得税: ￥%.2f元' % tax)
print('实际到手收入: ￥%.2f元' % (diff + 3500 - tax))

"""
用户身份验证
"""
# import getpass
# from getpass import getpass
# from getpass import *

username = input('请输入用户名: ')
password = input('请输入口令: ')
# 输入口令的时候终端中没有回显
# password = getpass.getpass('请输入口令: ')
if username == 'admin' and password == '123456':
    print('身份验证成功!')
else:
    print('身份验证失败!')

"""
输入一个正整数判断它是不是素数
"""
from math import sqrt

num = int(input('请输入一个正整数: '))
end = int(sqrt(num))
is_prime = True
for x in range(2, end + 1):
    if num % x == 0:
        is_prime = False
        break
if is_prime and num != 1:
    print('%d是素数' % num)
else:
    print('%d不是素数' % num)

"""
输入两个正整数计算最大公约数和最小公倍数
"""

x = int(input('x = '))
y = int(input('y = '))
if x > y:
    (x, y) = (y, x)
for factor in range(x, 0, -1):
    if x % factor == 0 and y % factor == 0:
        print('%d和%d的最大公约数是%d' % (x, y, factor))
        print('%d和%d的最小公倍数是%d' % (x, y, x * y // factor))
        break

"""
打印各种三角形图案
*
**
***
****
*****
    *
   **
  ***
 ****
*****
    *
   ***
  *****
 *******
*********
"""

row = int(input('请输入行数: '))
for i in range(row):
    for _ in range(i + 1):
        print('*', end='')
    print()

for i in range(row):
    for j in range(row):
        if j < row - i - 1:
            print(' ', end='')
        else:
            print('*', end='')
    print()

for i in range(row):
    for _ in range(row - i - 1):
        print(' ', end='')
    for _ in range(2 * i + 1):
        print('*', end='')
    print()

"""
用for循环实现1~100求和
"""

sum = 0
for x in range(1, 101):
    sum += x
print(sum)

"""
用while循环实现1~100求和
"""

sum = 0
num = 1
while num <= 100:
    sum += num
    num += 1
print(sum)

"""
用for循环实现1~100之间的偶数求和
"""

sum = 0
for x in range(2, 101, 2):
    sum += x
print(sum)

"""
用while循环实现1~100之间的偶数求和
"""

sum, num = 0, 2
while num <= 100:
    sum += num
    num += 2
print(sum)

"""
输入非负整数n计算n!
"""

n = int(input('n = '))
result = 1
for x in range(1, n + 1):
    result *= x
print('%d! = %d' % (n, result))