如何從JSON中的字典列表中刪除字典

Question

我的聯系人存儲在JSON文件的詞典列表中。 我希望能夠通過用戶輸入刪除聯系人。 我該怎么做呢？ 我嘗試使用for循環和彈出，但沒有用。

# Import Collections to use Ordered Dictionary
import collections

# Module used to save contacts to database
import json

# The main class
def main():

    # Creates an empty list of contacts
    contacts = []

    loop = True

    # Create a while loop for the menu that keeps looping for user input until loop = 0
    while loop == True:

        # Prints menu for the user in command line
        print """
        Contact Book App
        a) New Contact
        b) List Contacts
        c) Search Contacts
        d) Delete Contact
        e) Quit
         """

        # Asks for users input from a-e
        userInput = raw_input("Please select an option: ").lower()

        # OPTION 1 : ADD NEW CONTACT
        if userInput == "a":
            contact = collections.OrderedDict()

            contact['name'] = raw_input("Enter name: ").title()
            contact['phone'] = raw_input("Enter phone: ")
            contact['email'] = raw_input("Enter email: ")

            contacts.append(contact)
            json.dump(contacts, open('contacts.json','w'))

            print "Contact Added!"
            # For Debugging Purposes
            # print(contacts)

        # OPTION 2 : LIST ALL CONTACTS
        elif userInput == "b":
            print "Listing Contacts"
            try:
                contacts = json.load(open('contacts.json','r'))
            except:
                contacts = []

            print "%-30s %-30s %-30s" % ('NAME','PHONE','EMAIL')
            for i in contacts:
                print "%-30s %-30s %-30s" % (i['name'], i['phone'], i['email'])

        # OPTION 3 : SEARCH CONTACTS
        elif userInput == "c":
            print "Searching Contacts"
            search = raw_input("Please enter name: ")
            # Want to be able to search contacts by name, phone number or email
            try:
                contacts = json.load(open('contacts.json','r'))
            except:
                contacts = []

            for i in contacts:
                if i['name'] == search:
                    print i['name'], i['phone'], i['email']
                elif i['phone'] == search:
                    print i['name'], i['phone'], i['email']
                elif i['email'] == search:
                    print i['name'], i['phone'], i['email']
                else:
                    print "No Such Contact"

        # OPTION 4 : DELETE A CONTACT
        elif userInput == "d":
            print "Deleting Contact"
            deleteQuery = raw_input("Enter Contact Name: ")
            obj = json.load(open('contacts.json'))

            for i in contacts(len(obj)):
                if obj[i]['name'] == deleteQuery:
                    obj.pop(i)


        # OPTION 5 : QUIT PROGRAM
        elif userInput == "e":
            print "Quitting Contact Book"
            loop = False
        else:
            print "Invalid Input! Try again."


main()

Answer 1

您走在正確的軌道上，流行音樂應該起作用。 我更改了您的代碼，以便“聯系人”是字典而不是列表。 那么記錄可以如下所示：

contacts = {'Aname':{'name': name,
                     'phone': phone,
                     'email': email
                     },
            'Bname':{'name': name,
                     'phone': phone,
                     'email': email
                    }
           }

然后，您可以將名稱用作保存名稱，電話和電子郵件的嵌套字典對象的鍵。 刪除名稱現在可以使用contacts.pop（contact_name）。 我對代碼進行了一些更改以實現此目的。

# Import Collections to use Ordered Dictionary
import collections

# Module used to save contacts to database
import json

# The main class
def main():

    # Creates an empty list of contacts
    contacts = collections.OrderedDict()
    loop = True

    # Create a while loop for the menu that keeps looping for user input until loop = 0
    while loop == True:

        # Prints menu for the user in command line
        print """
        Contact Book App
        a) New Contact
        b) List Contacts
        c) Search Contacts
        d) Delete Contact
        e) Quit
         """

        # Asks for users input from a-e
        userInput = raw_input("Please select an option: ").lower()

        # OPTION 1 : ADD NEW CONTACT
        if userInput == "a":
            contact_name = raw_input("Enter name: ").title()

            contacts[contact_name] = {'name': contact_name,
                                     'phone': raw_input("Enter phone: "),
                                     'email': raw_input("Enter email: ")
                                     }

            json.dump(contacts, open('contacts.json','w'))

            print "Contact Added!"
            # For Debugging Purposes
            # print(contacts)

        # OPTION 2 : LIST ALL CONTACTS
        elif userInput == "b":
            print "Listing Contacts"
            try:
                contacts = json.load(open('contacts.json','r'))
                name_keys = list(contacts.keys())
            except:
                contacts = {}

            print "%-30s %-30s %-30s" % ('NAME','PHONE','EMAIL')

            for k in name_keys:
                print "%-30s %-30s %-30s" % (contacts[k]['name'], contacts[k]['phone'], contacts[k]['email'])

        # OPTION 3 : SEARCH CONTACTS
        elif userInput == "c":
            print "Searching Contacts"
            search = raw_input("Please enter name: ")
            # Want to be able to search contacts by name, phone number or email
            try:
                contacts = json.load(open('contacts.json','r'))
            except:
                contacts = []

            try:
                print "%-30s %-30s %-30s" % (contacts[search]['name'], contacts[search]['phone'], contacts[search]['email'])
            except KeyError:
                print "Not Found"

        # OPTION 4 : DELETE A CONTACT
        elif userInput == "d":
            print "Deleting Contact"
            contact_name = raw_input("Enter Contact Name: ")
            contacts = json.loads(open('contacts.json').read())

            try:
                contacts.pop(contact_name)
                json.dump(contacts, open('contacts.json','w'))
            except KeyError:
                print "Contact Not Found"


        # OPTION 5 : QUIT PROGRAM
        elif userInput == "e":
            print "Quitting Contact Book"
            loop = False
        else:
            print "Invalid Input! Try again."


main()

Answer 2

python for循環語法指定它經過可迭代。 len返回一個不可迭代的整數。 這就是為什么它不刪除； 它實際上並沒有通過for循環。 要解決此問題，請使用range函數創建一個可迭代范圍以如下方式遍歷列表：

for i in range(len(obj)):
    #etc