Python教程-基于菜单的Python程序

介绍菜单驱动程序

菜单驱动程序是一种通过显示选项列表（称为菜单）来从用户那里获取输入的程序，用户可以从中选择他们的选项。处理菜单驱动程序的系统有各种各样，从由微处理器控制的洗衣机到自动取款机（ATM）。以ATM为例，用户按单个键来指示交易类型（用户是否需要一张现金收据，或者需要账户对账单）。对于许多情况，用户按单个键来指示取款金额。

菜单驱动系统有两个好处：首先，通过单个按键输入，减少了系统对用户错误的敏感性。其次，菜单驱动系统限制了字符范围，使输入变得明确无误。因此，这两个特性使整个系统非常用户友好。

在接下来的教程中，我们将了解一些用Python编写的菜单驱动程序示例。这些程序将帮助我们了解菜单驱动程序的不同方面，以及Python编程语言的不同库和模块。

那么，让我们开始吧。

使用函数计算不同形状的参数和面积

程序：

# defining functions  
def p_circle(radius):  
    para = 2 * 3.14 * radius  
    print("Parameter of Circle:", para)  
  
def p_rectangle(height, width):  
    para = 2 * (height + width)  
    print("Parameter of Rectangle:", para)  
  
def p_square(side):  
    para = 4 * side  
    print("Parameter of Square:", para)  
  
def a_circle(radius):  
    area = 3.14 * radius * radius  
    print("Area of Circle:", area)  
  
def a_rectangle(height, width):  
    area = height * width  
    print("Area of Rectangle:", area)  
  
def a_square(side):  
    area = side * side  
    print("Area of Square:", area)  
  
# printing the starting line  
print("WELCOME TO A SIMPLE MENSURATION PROGRAM")  
  
# creating options  
while True:  
    print("\nMAIN MENU")  
    print("1. Calculate Parameter")  
    print("2. Calculate Area")  
    print("3. Exit")  
    choice1 = int(input("Enter the Choice:"))  
  
    if choice1 == 1:  
        print("\nCALCULATE PARAMETER")  
        print("1. Circle")  
        print("2. Rectangle")  
        print("3. Square")  
        print("4. Exit")  
        choice2 = int(input("Enter the Choice:"))  
  
        if choice2 == 1:  
            radius = int(input("Enter Radius of Circle:"))  
            p_circle(radius)  
              
        elif choice2 == 2:  
            height = int(input("Enter Height of Rectangle:"))  
            width = int(input("Enter Width of Rectangle:"))  
            p_rectangle(height, width)  
              
        elif choice2 == 3:  
            side = int(input("Enter Side of Square:"))  
            p_square(side)  
  
        elif choice2 == 4:  
            break  
              
        else:  
            print("Oops! Incorrect Choice.")  
      
    elif choice1 == 2:  
        print("\nCALCULATE AREA")  
        print("1. Circle")  
        print("2. Rectangle")  
        print("3. Square")  
        print("4. Exit")  
        choice3 = int(input("Enter the Choice:"))  
  
        if choice3 == 1:  
            radius = int(input("Enter Radius of Circle:"))  
            a_circle(radius)  
              
        elif choice3 == 2:  
            height = int(input("Enter Height of Rectangle:"))  
            width = int(input("Enter Width of Rectangle:"))  
            a_rectangle(height, width)  
              
        elif choice3 == 3:  
            side = int(input("Enter Side of Square:"))  
            a_square(side)  
  
        elif choice3 == 4:  
            break  
              
        else:  
            print("Oops! Incorrect Choice.")  
      
    elif choice1 == 3:  
        break  
      
    else:  
        print("Oops! Incorrect Choice.")  

输出：

WELCOME TO A SIMPLE MENSURATION PROGRAM

MAIN MENU
1. Calculate Parameter
2. Calculate Area
3. Exit
Enter the Choice:1

CALCULATE PARAMETER
1. Circle
2. Rectangle
3. Square
4. Exit
Enter the Choice:2
Enter Height of Rectangle:4
Enter Width of Rectangle:5
Parameter of Rectangle: 18

MAIN MENU
1. Calculate Parameter
2. Calculate Area
3. Exit
Enter the Choice:2

CALCULATE AREA
1. Circle
2. Rectangle
3. Square
4. Exit
Enter the Choice:1
Enter Radius of Circle:2
Area of Circle: 12.56

MAIN MENU
1. Calculate Parameter
2. Calculate Area
3. Exit
Enter the Choice:5
Oops! Incorrect Choice.

MAIN MENU
1. Calculate Parameter
2. Calculate Area
3. Exit
Enter the Choice:3

解释：

在上面的示例中，我们定义了不同的函数来打印计算后的估计值。这些函数包括圆、矩形和正方形的参数和面积。然后，我们打印了程序的标题，即欢迎使用简单的测量程序。在此之下，我们使用无限的while循环来打印包含不同选项的主菜单。然后，程序使用if-elif-else语句要求用户输入整数以选择选项。如果插入的整数不在选项列表中，程序将引发异常。然后，我们创建了两个不同的子菜单，分别描述参数选项和面积选项。然后，我们在这些子菜单中添加了一些更多的选项，描述不同的形状。这些选项还接受不同的整数值，表示圆的半径、矩形的高度和宽度，以及正方形的边长。结果，菜单驱动程序成功创建，并能够计算不同形状的参数和面积。

创建一个简单计算器的菜单驱动程序

在下面的菜单驱动程序中，我们将构建一个简单的Python计算器。我们将使用无限的while循环和与上面相同的函数。我们将设计一个菜单，允许用户与计算器功能进行交互，如加法、减法、乘法和除法。

让我们考虑以下程序的语法：

程序：

# defining addition function  
def add(a, b):  
    sum = a + b  
    print(a, "+", b, "=", sum)  
  
# defining subtraction function  
def subtract(a, b):  
    difference = a - b  
    print(a, "-", b, "=", difference)  
  
# defining multiplication function  
def multiply(a, b):  
    product = a * b  
    print(a, "x", b, "=", product)  
  
# defining division function  
def divide(a, b):  
    division = a / b  
    print(a, "/", b, "=", division)  
  
# printing the heading  
print("WELCOME TO A SIMPLE CALCULATOR")  
  
# using the while loop to print menu list  
while True:  
    print("\nMENU")  
    print("1. Sum of two Numbers")  
    print("2. Difference between two Numbers")  
    print("3. Product of two Numbers")  
    print("4. Division of two Numbers")  
    print("5. Exit")  
    choice = int(input("\nEnter the Choice: "))  
  
# using if-elif-else statement to pick different options  
    if choice == 1:  
        print( "\nADDITION\n")  
        a = int( input("First Number: "))  
        b = int( input("Second Number: "))  
        add(a, b)  
  
    elif choice == 2:  
        print( "\nSUBTRACTION\n")  
        a = int( input("First Number: "))  
        b = int( input("Second Number: "))  
        subtract(a, b)  
  
    elif choice == 3:  
        print( "\nMULTIPLICATION\n")  
        a = int( input("First Number: "))  
        b = int( input("Second Number: "))  
        multiply(a, b)  
  
    elif choice == 4:  
        print( "\nDIVISION\n")  
        a = int( input("First Number: "))  
        b = int( input("Second Number: "))  
        divide(a, b)  
  
    elif choice == 5:  
        break  
      
    else:  
        print( "Please Provide a valid Input!") 

输出：

WELCOME TO A SIMPLE CALCULATOR

MENU
1. Sum of two Numbers
2. Difference between two Numbers
3. Product of two Numbers
4. Division of two Numbers
5. Exit

Enter the Choice: 1

ADDITION

First Number: 3
Second Number: 4
3 + 4 = 7

MENU
1. Sum of two Numbers
2. Difference between two Numbers
3. Product of two Numbers
4. Division of two Numbers
5. Exit

Enter the Choice: 2

SUBTRACTION

First Number: 6
Second Number: 3
6 - 3 = 3

MENU
1. Sum of two Numbers
2. Difference between two Numbers
3. Product of two Numbers
4. Division of two Numbers
5. Exit

Enter the Choice: 3

MULTIPLICATION

First Number: 8
Second Number: 2
8 x 2 = 16

MENU
1. Sum of two Numbers
2. Difference between two Numbers
3. Product of two Numbers
4. Division of two Numbers
5. Exit

Enter the Choice: 4

DIVISION

First Number: 10
Second Number: 4
10 / 4 = 2.5

MENU
1. Sum of two Numbers
2. Difference between two Numbers
3. Product of two Numbers
4. Division of two Numbers
5. Exit

Enter the Choice: 5

解释：

在上面的程序中，我们使用了几乎与前面的程序相同的流程。我们定义了各种函数，如加、减、乘和除。然后，我们使用while循环来打印菜单列表，供用户选择。然后，程序使用if-elif-else语句来返回用户需要的答案。结果，成功创建了一个简单的计算器，并执行了一些基本的计算，如加法、减法、乘法和除法。

创建一个电话目录的菜单驱动程序

在下面的菜单驱动程序中，我们将使用不同的函数创建一个电话簿目录。我们将为电话簿目录添加以下功能：

1. 存储人的联系号码
2. 使用人的姓名搜索联系号码

让我们在以下程序中实现这个想法：

程序：

# printing the heading of the program  
print( "WELCOME TO THE PHONEBOOK DIRECTORY")  
  
# creating a .txt file to store contact details  
filename = "myphonebook.txt"  
myfile = open(filename, "a+")  
myfile.close  
  
# defining main menu  
def main_menu():  
    print( "\nMAIN MENU\n")  
    print( "1. Show all existing Contacts")  
    print( "2. Add a new Contact")  
    print( "3. Search the existing Contact")  
    print( "4. Exit")  
    choice = input("Enter your choice: ")  
    if choice == "1":  
        myfile = open(filename, "r+")  
        filecontents = myfile.read()  
        if len(filecontents) == 0:  
            print( "There is no contact in the phonebook.")  
        else:  
            print(filecontents)  
        myfile.close  
        enter = input("Press Enter to continue ...")  
        main_menu()  
    elif choice == "2":  
        newcontact()  
        enter = input("Press Enter to continue ...")  
        main_menu()  
    elif choice == "3":  
        searchcontact()  
        enter = input("Press Enter to continue ...")  
        main_menu()  
    elif choice == "4":  
        print("Thank you for using Phonebook!")  
    else:  
        print( "Please provide a valid input!\n")  
        enter = input( "Press Enter to continue ...")  
        main_menu()  
  
# defining search function          
def searchcontact():  
    searchname = input( "Enter First name for Searching contact record: ")  
    remname = searchname[1:]  
    firstchar = searchname[0]  
    searchname = firstchar.upper() + remname  
    myfile = open(filename, "r+")  
    filecontents = myfile.readlines()  
       
    found = False  
    for line in filecontents:  
        if searchname in line:  
            print( "Your Required Contact Record is:", end = " ")  
            print( line)  
            found = True  
            break  
    if found == False:  
        print( "The Searched Contact is not available in the Phone Book", searchname)  
  
# first name  
def input_firstname():  
    first = input( "Enter your First Name: ")  
    remfname = first[1:]  
    firstchar = first[0]  
    return firstchar.upper() + remfname  
  
# last name  
def input_lastname():  
    last = input( "Enter your Last Name: ")  
    remlname = last[1:]  
    firstchar = last[0]  
    return firstchar.upper() + remlname  
  
# storing the new contact details  
def newcontact():  
    firstname = input_firstname()  
    lastname = input_lastname()  
    phoneNum = input( "Enter your Phone number: ")  
    emailID = input( "Enter your E-mail Address: ")  
    contactDetails = ("[" + firstname + " " + lastname + ", " + phoneNum + ", " + emailID +  "]\n")  
    myfile = open(filename, "a")  
    myfile.write(contactDetails)  
    print( "The following Contact Details:\n " + contactDetails + "\nhas been stored successfully!")  
  
main_menu()  

输出：

WELCOME TO THE PHONEBOOK DIRECTORY

MAIN MENU

1. Show all existing Contacts
2. Add a new Contact
3. Search the existing Contact
4. Exit
Enter your choice: 1
There is no contact in the phonebook.
Press Enter to continue ...

MAIN MENU

1. Show all existing Contacts
2. Add a new Contact
3. Search the existing Contact
4. Exit
Enter your choice: 2
Enter your First Name: Mark
Enter your Last Name: Henry
Enter your Phone number: 1234567890
Enter your E-mail Address: iammark@example.com
The following Contact Details:
 [Mark Henry, 1234567890, iammark@example.com]

has been stored successfully!
Press Enter to continue ...

MAIN MENU

1. Show all existing Contacts
2. Add a new Contact
3. Search the existing Contact
4. Exit
Enter your choice: 3
Enter First name for Searching contact record: Mark
Your Required Contact Record is: [Mark Henry, 1234567890, iammark@example.com]

Press Enter to continue ...

MAIN MENU

1. Show all existing Contacts
2. Add a new Contact
3. Search the existing Contact
4. Exit
Enter your choice: 1
[Mark Henry, 1234567890, iammark@example.com]

Press Enter to continue ...

MAIN MENU

1. Show all existing Contacts
2. Add a new Contact
3. Search the existing Contact
4. Exit
Enter your choice: 4
Thank you for using Phonebook!

解释：

在上面的菜单驱动程序中，我们创建了一个电话簿目录，可以将新联系存储在文本文件中，显示存储的联系方式，并允许用户搜索现有号码。首先，我们创建一个文本文件来存储联系详细信息。然后，我们定义了各种函数，用于添加、显示和搜索不同的联系人。我们还创建了不同的联系人详细信息字段，如名字、姓氏、手机号码和电子邮件地址。结果，程序成功完成，其输出如上所示。

结论

在上面的教程中，我们理解了菜单驱动编程的含义，以及一些示例。我们创建了三个不同的程序，包括测量程序、简单计算器和电话簿目录。除了这三个示例之外，还可以创建许多其他程序。