Python 在csv文件中写入嵌套字典，但每次在csv文件中都会重复/追加头

我是python的新手。我已经编写了在csv文件中附加嵌套字典的代码。但每次我运行代码时，标题也会被忽略

但是我需要，头应该只需要在csv文件中附加一次，而不是更多

你有没有建议对我有帮助的修改

提前谢谢

                       CSV file output

CSV文件截图

---

在while循环之前，检查文件是否存在；如果没有；创建带有标题的文件。在循环中只写行。

我尝试了这个file.tell（）方法，它工作得很好！！无论如何，谢谢你的回答

with open('Employee Details.csv', 'a') as csvfile:
     csv_columns = ['User ID', 'Name', 'Age', 'Occupation', 'Department', 'Salary', 'Address']
     writer = csv.DictWriter(csvfile, fieldnames=csv_columns)

# using  file.tell we can verify the position whether there is any content in the position by specifying the value is 0

    if csvfile.tell() == 0:
       writer.writeheader()

    for key,value in user_details.items():
        row = {'User ID': key}
        row.update(value)
        writer.writerow(row)

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你认为

writer.writeheader（）

可以做什么？您将以追加模式在

a

中打开CSV文件-因此，您的输出将在已经存在的所有内容之后写入。请不要发布代码/数据/回溯的图像。只需复制文本，粘贴到问题中，并将其格式化为代码。。数据的一个最小示例。

import csv

user_details = {}

while True:
    user_input = input(" You're Operation Please ( New / View ) Details : ").lower()

    if user_input == 'new':
        create_user_ID = input(" Enter the user ID :  ")
        user_details[create_user_ID] = {}
        user_name = input(" Enter the user name : ")
        user_details[create_user_ID]['Name'] = user_name
        user_age = int(input(" Enter the Age : "))
        user_details[create_user_ID]['Age'] = user_age
        user_occupation = input(" Enter the users occupation : ")
        user_details[create_user_ID]['Occupation'] = user_occupation
        user_department = input(" user department : ")
        user_details[create_user_ID]['Department'] = user_department
        user_income = int(input(" Enter the salary details : "))
        user_details[create_user_ID]['Salary'] = user_income
        user_address = input(" Enter the Address details ")
        user_details[create_user_ID]['Address'] = user_address

        print(f" New User account {create_user_ID} has been successfully created")

# Need to clarify this step,but program is running without any issues

        with open('Employee Details.csv', 'a') as csvfile:
            csv_columns = ['User ID', 'Name', 'Age', 'Occupation', 'Department', 'Salary', 'Address']
            writer = csv.DictWriter(csvfile, fieldnames=csv_columns)

            writer.writeheader()
            for key,value in user_details.items():
                row = {'User ID': key}
                row.update(value)
                writer.writerow(row)

        process = input(" Do you want to continue the Account creation process (YES / NO ) : ").lower()
        if process == 'no':
            break

    elif user_input == 'view':
        user_ID = input("Enter the user_ID : ")
        print(user_details[user_ID])
        break

    else:
        print(" Please enter the proper command to execute (new / view)")

for detail in user_details.items():
    print(detail)

with open('Employee Details.csv', 'a') as csvfile:
     csv_columns = ['User ID', 'Name', 'Age', 'Occupation', 'Department', 'Salary', 'Address']
     writer = csv.DictWriter(csvfile, fieldnames=csv_columns)

# using  file.tell we can verify the position whether there is any content in the position by specifying the value is 0

    if csvfile.tell() == 0:
       writer.writeheader()

    for key,value in user_details.items():
        row = {'User ID': key}
        row.update(value)
        writer.writerow(row)