2018-05-17 4,055 views 评论

《Python语言程序设计基础》课后习题程序整理（第2~4章）

程序大多数为自己编写，程序可能不是最优，复杂度不是最好，也有可能存在理解错题意的问题，敬请谅解。

习题内容为高等教育出版社出版的由嵩天教授等编写的《Python语言程序设计基础（第2版）》中的习题内容。

第二章：Python程序实例解析

1.请使用turtle库函数绘制一个包含9个同心圆的靶盘

import&nbsp;turtle
def&nbsp;bapan(radius):
&nbsp;&nbsp;&nbsp;&nbsp;turtle.penup()
&nbsp;&nbsp;&nbsp;&nbsp;turtle.goto(0,-radius)
&nbsp;&nbsp;&nbsp;&nbsp;turtle.pendown()
&nbsp;&nbsp;&nbsp;&nbsp;turtle.circle(radius,360)
&nbsp;
turtle.pensize(2)
turtle.pencolor(&#39;red&#39;)
for&nbsp;i&nbsp;in&nbsp;range(10,100,10):
&nbsp;&nbsp;&nbsp;&nbsp;bapan(i)
turtle.done()

import turtle

def bapan(radius):

    turtle.penup()

    turtle.goto(0,-radius)

    turtle.pendown()

    turtle.circle(radius,360)

turtle.pensize(2)

turtle.pencolor('red')

for i in range(10,100,10):

    bapan(i)

turtle.done()

程序练习题2.1 实例1的修改。改造实例代码1.1，采用eval(input(<提示内容>))替换现有输入部分，并使输出的温度值为正数

TempStr&nbsp;=&nbsp;eval(&#39;input(&quot;请输入需要转换的温度：&quot;)&#39;)
if&nbsp;TempStr[-1]&nbsp;in&nbsp;[&#39;F&#39;,&#39;f&#39;]:
&nbsp;&nbsp;&nbsp;&nbsp;C=int((eval(TempStr[0:-1])-32)/1.8)
&nbsp;&nbsp;&nbsp;&nbsp;print(&quot;转换后的温度速{:d}C&quot;.format(C))
elif&nbsp;TempStr[-1]&nbsp;in&nbsp;[&#39;C&#39;,&#39;c&#39;]:
&nbsp;&nbsp;&nbsp;&nbsp;F=int(1.8*eval(TempStr[0:-1])+32)
&nbsp;&nbsp;&nbsp;&nbsp;print(&quot;转换后的温度速{:d}F&quot;.format(F))
else:
&nbsp;&nbsp;&nbsp;&nbsp;print(&quot;ERROR&quot;)

TempStr = eval('input("请输入需要转换的温度：")')

if TempStr[-1] in ['F','f']:

    C=int((eval(TempStr[0:-1])-32)/1.8)

    print("转换后的温度速{:d}C".format(C))

elif TempStr[-1] in ['C','c']:

    F=int(1.8*eval(TempStr[0:-1])+32)

    print("转换后的温度速{:d}F".format(F))

else:

    print("ERROR")

程序练习题2.2 汇率兑换程序。按照温度转换程序的设计思路，按照1美元=6.36人民币汇率编写一个美元和人民币双向兑换程序。

value&nbsp;=&nbsp;input(&quot;请输入要转换的数额，
务必在输入数值前输入USD或RMB以表明货币类型：\n&quot;)
result&nbsp;=&nbsp;0
if&nbsp;value[0:3]&nbsp;==&nbsp;&quot;RMB&quot;:
&nbsp;&nbsp;&nbsp;&nbsp;result&nbsp;=&nbsp;eval(value[3:])&nbsp;/&nbsp;6.36
&nbsp;&nbsp;&nbsp;&nbsp;print(&quot;USD{:.2f}&quot;.format(result))
elif&nbsp;value[0:3]&nbsp;==&nbsp;&quot;USD&quot;:
&nbsp;&nbsp;&nbsp;&nbsp;result&nbsp;=&nbsp;(eval(value[3:])*&nbsp;6.36)
&nbsp;&nbsp;&nbsp;&nbsp;print(&quot;RMB{:.2f}&quot;.format(result))

value = input("请输入要转换的数额，

务必在输入数值前输入USD或RMB以表明货币类型：\n")

result = 0

if value[0:3] == "RMB":

    result = eval(value[3:]) / 6.36

    print("USD{:.2f}".format(result))

elif value[0:3] == "USD":

    result = (eval(value[3:])* 6.36)

    print("RMB{:.2f}".format(result))

程序练习题2.3 实例2的修改。改造实例代码2.1，绘制一条彩色蟒蛇，即在绘制Python蟒蛇的每一小段，画笔的绘制颜色会发生变化。

import&nbsp;turtle
color=[&#39;grey&#39;,&#39;darkgreen&#39;,&#39;gold&#39;,&#39;violet&#39;]
turtle.setup(650,&nbsp;350,&nbsp;200,&nbsp;200)
turtle.penup()
turtle.fd(-250)
turtle.pendown()
turtle.pensize(14)
turtle.seth(-40)
for&nbsp;i&nbsp;in&nbsp;range(4):
&nbsp;&nbsp;&nbsp;&nbsp;turtle.pencolor(color[i])
&nbsp;&nbsp;&nbsp;&nbsp;turtle.circle(40,&nbsp;80)
&nbsp;&nbsp;&nbsp;&nbsp;turtle.circle(-40,&nbsp;80)
turtle.pencolor(&quot;red&quot;)
turtle.circle(40,&nbsp;80/2)
turtle.pencolor(&quot;blue&quot;)
turtle.fd(40)
turtle.pencolor(&quot;pink&quot;)
turtle.circle(16,&nbsp;180)
turtle.fd(40&nbsp;*&nbsp;2/3)
turtle.done()

import turtle

color=['grey','darkgreen','gold','violet']

turtle.setup(650, 350, 200, 200)

turtle.penup()

turtle.fd(-250)

turtle.pendown()

turtle.pensize(14)

turtle.seth(-40)

for i in range(4):

    turtle.pencolor(color[i])

    turtle.circle(40, 80)

    turtle.circle(-40, 80)

turtle.pencolor("red")

turtle.circle(40, 80/2)

turtle.pencolor("blue")

turtle.fd(40)

turtle.pencolor("pink")

turtle.circle(16, 180)

turtle.fd(40 * 2/3)

turtle.done()

程序练习题2.4 等边三角形的绘制。使用turtle库中的turtle.fd()函数和turtle.seth()函数绘制一个等边三角形。

import&nbsp;turtle
def&nbsp;Dengbian(N):
&nbsp;&nbsp;&nbsp;&nbsp;turtle.fd(N)
&nbsp;&nbsp;&nbsp;&nbsp;turtle.seth(120)
&nbsp;&nbsp;&nbsp;&nbsp;turtle.fd(N)
&nbsp;&nbsp;&nbsp;&nbsp;turtle.seth(240)
&nbsp;&nbsp;&nbsp;&nbsp;turtle.fd(N)
&nbsp;&nbsp;&nbsp;&nbsp;turtle.done()
Bc=&nbsp;input(&quot;请输入边长&quot;)
Dengbian(eval(Bc))

import turtle

def Dengbian(N):

    turtle.fd(N)

    turtle.seth(120)

    turtle.fd(N)

    turtle.seth(240)

    turtle.fd(N)

    turtle.done()

Bc= input("请输入边长")

Dengbian(eval(Bc))

程序练习题2.8 正方形螺旋线的绘制。利用turtle库绘制一个正方形螺旋线。

import&nbsp;turtle
turtle.pensize(2)
turtle.pencolor(&quot;blue&quot;)
for&nbsp;i&nbsp;in&nbsp;range(90):
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;turtle.forward(2*i)
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;turtle.left(90)
turtle.done()

import turtle

turtle.pensize(2)

turtle.pencolor("blue")

for i in range(90):

     turtle.forward(2*i)

     turtle.left(90)

turtle.done()

第三章：基本数据类型

实例3.2反转：凯撒密码解密

miwen&nbsp;=&nbsp;input(&quot;请输入密文：&quot;)
for&nbsp;p&nbsp;in&nbsp;miwen:
&nbsp;&nbsp;&nbsp;&nbsp;if&nbsp;ord(&quot;a&quot;)&lt;=ord(p)&lt;=ord(&quot;z&quot;):
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;print(chr(ord(&quot;a&quot;)+(ord(p)-ord(&quot;a&quot;)-3)%26),end=&#39;&#39;)
&nbsp;&nbsp;&nbsp;&nbsp;else:
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;print(p,end=&#39;&#39;)

miwen = input("请输入密文：")

for p in miwen:

    if ord("a")<=ord(p)<=ord("z"):

        print(chr(ord("a")+(ord(p)-ord("a")-3)%26),end='')

    else:

        print(p,end='')

习题3.1 重量计算。月球上物体的体重是地球上的16.5%没加入你在地球上每年增长0.5kg，编写程序输出未来10年你在地球和月球上的体重状况。

weight&nbsp;=&nbsp;input(&quot;请输入你的体重（以千克为单位）&quot;)
weight&nbsp;=&nbsp;eval(weight)
wei_mon&nbsp;=&nbsp;weight*0.165
print(&quot;你现在在地球上的体重为{:.2f}kg，你现在在月球的体重为{:.2f}kg&quot;\
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;.format(weight,wei_mon))
for&nbsp;i&nbsp;in&nbsp;range(11):
&nbsp;&nbsp;&nbsp;&nbsp;weight&nbsp;+=0.5
wei_mon&nbsp;=&nbsp;weight*0.165
print(&quot;你10年后在地球上的体重为{:.2f}kg，你10年后在月球的体重为{:.2f}kg&quot;\
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;.format(weight,wei_mon))

weight = input("请输入你的体重（以千克为单位）")

weight = eval(weight)

wei_mon = weight*0.165

print("你现在在地球上的体重为{:.2f}kg，你现在在月球的体重为{:.2f}kg"\

      .format(weight,wei_mon))

for i in range(11):

    weight +=0.5

wei_mon = weight*0.165

print("你10年后在地球上的体重为{:.2f}kg，你10年后在月球的体重为{:.2f}kg"\

      .format(weight,wei_mon))

习题3.4 回文数判断。设n是以任意自然数，如果n的个位数字反向排列所得到的结果与n相等，则n被称为回文数。从键盘输入一个5位数字，判断其是不是回文数。

num&nbsp;=&nbsp;input(&quot;请输入一个五位数字&quot;)
if(len(num)!=5):
&nbsp;&nbsp;&nbsp;&nbsp;print(&quot;不是回文数&quot;)
else:
&nbsp;&nbsp;&nbsp;&nbsp;if((eval(num[0])==eval(num[4]))&nbsp;and&nbsp;(eval(num[1])==eval(num[3]))):
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;print(&quot;是回文数&quot;)
&nbsp;&nbsp;&nbsp;&nbsp;else:
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;print(&quot;不是回文数&quot;)

num = input("请输入一个五位数字")

if(len(num)!=5):

    print("不是回文数")

else:

    if((eval(num[0])==eval(num[4])) and (eval(num[1])==eval(num[3]))):

        print("是回文数")

    else:

        print("不是回文数")

第四章：程序的控制结构

习题4.1（按照习题4.4和4.5来做）猜数字游戏。让计算机随机产生一个预设数字，范围在0-9以内，让用户通过键盘输入所猜的数字，如果大于预设的数，显示“遗憾，太大了”；如果小于预设的数，显示“遗憾，太小了”，如此循环，直到猜中该数，显示“预测N次，终于猜中了！”。当用户输入的不是整数时，程序会自动退出执行并显示“输入内容必须为整数！”

from&nbsp;random&nbsp;import&nbsp;*
def&nbsp;input_num():
&nbsp;&nbsp;&nbsp;&nbsp;you_num&nbsp;=&nbsp;input(&quot;请输入您猜的数字&quot;)
&nbsp;&nbsp;&nbsp;&nbsp;you_num&nbsp;=&nbsp;eval(you_num)
&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;you_num
&nbsp;
num&nbsp;=&nbsp;randint(0,9)
you_num&nbsp;=&nbsp;input_num()
print(num)
n=1
try:
&nbsp;&nbsp;&nbsp;&nbsp;while(num!=you_num):
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;n&nbsp;+=&nbsp;1
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(you_num&lt;num):
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;print(&quot;遗憾，太小了&quot;)
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(you_num&gt;num):
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;print(&quot;遗憾，太大了&quot;)
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;you_num&nbsp;=&nbsp;input_num()
&nbsp;&nbsp;&nbsp;&nbsp;print(&quot;预测{}次，终于猜中了！&quot;.format(n))
except:
print(&quot;输入内容必须为整数！&quot;)

from random import *

def input_num():

    you_num = input("请输入您猜的数字")

    you_num = eval(you_num)

    return you_num

num = randint(0,9)

you_num = input_num()

print(num)

n=1

try:

    while(num!=you_num):

        n += 1

        if(you_num<num):

            print("遗憾，太小了")

        if(you_num>num):

            print("遗憾，太大了")

        you_num = input_num()

    print("预测{}次，终于猜中了！".format(n))

except:

print("输入内容必须为整数！")

习题4.2 统计不同字符个数。用户从键盘输入一行字符，统计并输出其中英文字符、数字和其它字符的个数。

import&nbsp;string
from&nbsp;collections&nbsp;import&nbsp;namedtuple
def&nbsp;str_count(s):
&nbsp;&nbsp;&nbsp;&nbsp;count_en&nbsp;=&nbsp;count_dg&nbsp;=&nbsp;count_sp&nbsp;=&nbsp;count_zh&nbsp;=&nbsp;count_oth&nbsp;=&nbsp;0
&nbsp;&nbsp;&nbsp;&nbsp;s_len&nbsp;=&nbsp;len(s)
&nbsp;&nbsp;&nbsp;&nbsp;for&nbsp;c&nbsp;in&nbsp;s:
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#英文
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if&nbsp;c&nbsp;in&nbsp;string.ascii_letters:
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;count_en&nbsp;+=&nbsp;1
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#数字
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;elif&nbsp;c.isdigit():
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;count_dg&nbsp;+=&nbsp;1
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#空格
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;elif&nbsp;c.isspace():
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;count_sp&nbsp;+=&nbsp;1
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#中文
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;elif&nbsp;c.isalpha():
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;count_zh&nbsp;+=&nbsp;1
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#其它特殊字符
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else:
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;count_oth&nbsp;+=&nbsp;1
&nbsp;&nbsp;&nbsp;&nbsp;total_chars&nbsp;=&nbsp;count_zh&nbsp;+&nbsp;count_en&nbsp;+&nbsp;count_sp&nbsp;+&nbsp;count_dg&nbsp;+&nbsp;count_oth
&nbsp;&nbsp;&nbsp;&nbsp;if&nbsp;total_chars&nbsp;==&nbsp;s_len:
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;namedtuple(&#39;Count&#39;,&nbsp;[&#39;total&#39;,&nbsp;&#39;zh&#39;,&nbsp;&#39;en&#39;,&nbsp;&#39;space&#39;,&nbsp;
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#39;digit&#39;,&nbsp;&#39;othher&#39;])(s_len,&nbsp;count_zh,&nbsp;count_en,&nbsp;count_sp,&nbsp;count_dg,&nbsp;count_oth)
&nbsp;&nbsp;&nbsp;&nbsp;else:
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;print(&#39;Something&nbsp;is&nbsp;wrong!&#39;)
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;None
&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;None
&nbsp;
&nbsp;
s&nbsp;=&nbsp;input(&quot;请输入你想统计的字符串。&quot;)
count&nbsp;=&nbsp;str_count(s)
print(s,&nbsp;end=&#39;\n\n&#39;)
print(&#39;该字符串共有&nbsp;{}&nbsp;个字符，其中有&nbsp;{}&nbsp;个汉字，{}&nbsp;个英文，{}&nbsp;个空格，{}&nbsp;
个数字，{}&nbsp;个标点符号。&#39;.format(count.total,&nbsp;count.zh,&nbsp;count.en,&nbsp;
count.space,&nbsp;count.digit,&nbsp;count.othher))

import string

from collections import namedtuple

def str_count(s):

    count_en = count_dg = count_sp = count_zh = count_oth = 0

    s_len = len(s)

    for c in s:

        #英文

        if c in string.ascii_letters:

            count_en += 1

        #数字

        elif c.isdigit():

            count_dg += 1

        #空格

        elif c.isspace():

            count_sp += 1

        #中文

        elif c.isalpha():

            count_zh += 1

        #其它特殊字符

        else:

            count_oth += 1

    total_chars = count_zh + count_en + count_sp + count_dg + count_oth

    if total_chars == s_len:

        return namedtuple('Count', ['total', 'zh', 'en', 'space', 

        'digit', 'othher'])(s_len, count_zh, count_en, count_sp, count_dg, count_oth)

    else:

        print('Something is wrong!')

        return None

s = input("请输入你想统计的字符串。")

count = str_count(s)

print(s, end='\n\n')

print('该字符串共有 {} 个字符，其中有 {} 个汉字，{} 个英文，{} 个空格，{} 

个数字，{} 个标点符号。'.format(count.total, count.zh, count.en, 

count.space, count.digit, count.othher))

习题4.6 羊车门问题。有3扇关闭的门，一扇门后面听着汽车，其余门后是山羊，只有主持人直到每扇门后面有什么，参赛者可以选择一扇门，在开启它之前，主持人会开启另外一扇门，露出门后的山羊，然后允许参赛者更换自己的选择。请问：才塞着更换选择后能否增加猜中汽车的机会？其使用random库对这个随机事件进行预测，分别给出参赛者改变选择和坚持选择获胜的概率。

from&nbsp;random&nbsp;import*
TIMES&nbsp;=&nbsp;input(&quot;请输入你想做的测试次数&quot;)
TIMES&nbsp;=&nbsp;eval(TIMES)
my_first_choice_n=0#初始化不改选择的次数
my_change_choice_n=0#初始化更改选择的次数
for&nbsp;i&nbsp;in&nbsp;range(TIMES):
&nbsp;&nbsp;&nbsp;&nbsp;a=&quot;羊1&quot;,&quot;羊2&quot;,&quot;车&quot;
&nbsp;&nbsp;&nbsp;&nbsp;car_inDoor=choice(a)
&nbsp;&nbsp;&nbsp;&nbsp;my_guess=choice(a)
&nbsp;&nbsp;&nbsp;&nbsp;if&nbsp;car_inDoor==my_guess:
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;my_first_choice_n+=1
&nbsp;&nbsp;&nbsp;&nbsp;else:
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;my_change_choice_n+=1
print(&quot;不改选择:{}&quot;.format(my_first_choice_n/TIMES))
print(&quot;更改选择:{}&quot;.format(my_change_choice_n/TIMES))

from random import*

TIMES = input("请输入你想做的测试次数")

TIMES = eval(TIMES)

my_first_choice_n=0#初始化不改选择的次数

my_change_choice_n=0#初始化更改选择的次数

for i in range(TIMES):

    a="羊1","羊2","车"

    car_inDoor=choice(a)

    my_guess=choice(a)

    if car_inDoor==my_guess:

        my_first_choice_n+=1

    else:

        my_change_choice_n+=1

print("不改选择:{}".format(my_first_choice_n/TIMES))

print("更改选择:{}".format(my_change_choice_n/TIMES))

习题4.7 用异常处理改造实例1，使其能够接受并处理用户的任何输入。

TempStr&nbsp;=&nbsp;input(&quot;请输入带有符号的温度值：&quot;)
try:
&nbsp;&nbsp;&nbsp;&nbsp;if&nbsp;TempStr[-1]&nbsp;in&nbsp;[&#39;F&#39;,&#39;f&#39;]:
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;C=(eval(TempStr[0:-1])-32)/1.8
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;print(&quot;转换后的温度是{:.2f}&nbsp;C&quot;.format(C))
&nbsp;&nbsp;&nbsp;&nbsp;elif&nbsp;TempStr[-1]&nbsp;in&nbsp;[&#39;C&#39;,&#39;f&#39;]:
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;F=(eval(TempStr[0:-1]))*1.8+32#[0:-1]代表从第一位到倒数第二位
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;print(&quot;转换后的温度是{:.2f}F&quot;.format(F))
&nbsp;&nbsp;&nbsp;&nbsp;else:
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;print(&quot;Format&nbsp;Error!!&quot;)
except:
&nbsp;&nbsp;&nbsp;&nbsp;print(&quot;输入错误，请严格按照规定输入信息！&quot;)