Question

我的代码每次创建相同的标题，我希望它创建一个并将数据附加到CSV而不创建新标题。

import csv

with open("Details.csv","a+") as Details:
    w=csv.writer(Details,delimiter=",")

    headers1=["Name","Age","Year Group"]
    line=Details.readlines()
    if line!=["Name","Age","Year Group"]:
        w.writerow(headers1)
    print("Welcome User, to my Topics Quiz!\n-------------------------------
    --------\nYou can choose from 3 different topics:\n  • History\n  •
    Music\n •  Computer Science\n---------------------------------------")
    print("Before we start, we need to register an account.")
    User=input("Enter your name:\n")
    Age=input("Enter your age:\n")
    Year=input("Enter your year group:\n")

    details=[User,Age,Year]
    w.writerow(details)
    Details.close()

with open("UserPass.csv","a+") as Userpass:
    w=csv.writer(Userpass,delimiter=",")
    headers2=["Username","Password"]
    if headers2 not in Userpass:
       w.writerow(headers2)

NewUser=(User[:3]+Age)
print("Great! Your username is set to: {}".format(NewUser))
Pass=input("Enter a password for your account:\n")
userpass=[NewUser,Pass]
w.writerow(userpass)
Userpass.close()

非常感谢任何帮助。

Answer 1

您的代码中存在不同的问题：

1）csv文件中包含数据的行之间的空行，由于非二进制类型的开放而发生，可以通过在open函数中添加arg来修复：

w=csv.writer(Details,delimiter=",",lineterminator='\n')

2）在你的情况下，Details.readlines（）方法返回[]，因为a +类型的开放，它应该在文件的末尾添加行，所以指针已经在最后了我们需要在开头使用该代码返回它：

line=Details.seek(0)

3）另外，我们只需要第一行，所以只需使用readline（）方法。毕竟，你的情况应该是这样的，因为返回类型以及每行末尾都有\ n的事实：

if line!="Name,Age,Year Group\n":

该部分的完整代码。让我知道它是否适合你：

w=csv.writer(Details,delimiter=",",lineterminator='\n')
headers1=["Name","Age","Year Group"]
line=Details.seek(0)
line=Details.readlines()[0]
print(line)
if line!="Name,Age,Year Group\n":
    w.writerow(headers1)

Answer 2

您正在以附加模式（https://docs.python.org/3/library/functions.html#open）打开文件，因此此line=Details.readlines()将始终为空行，并且每次都会写入您的标题（代码将始终进入，如果）。

与其他文件类似。因此，我建议您首先检查文件是否存在，如果没有创建并添加标题，则从with删除标题部分：

import csv import os.path if not os.path.isfile("Details.csv"): with open("Details.csv", "a+") as Details: w = csv.writer(Details, delimiter=",") headers1 = ["Name", "Age", "Year Group"] w.writerow(headers1) Details.close() if not os.path.isfile("UserPass.csv"): with open("UserPass.csv", "a+") as Userpass: w = csv.writer(Userpass, delimiter=",") headers2 = ["Username", "Password"] w.writerow(headers2) Userpass.close() with open("Details.csv", "a+") as Details: w = csv.writer(Details, delimiter=",") print("Welcome User, to my Topics Quiz!\n-------------------------------" "--------\nYou can choose from 3 different topics:\n • History\n • " "Music\n • Computer Science\n---------------------------------------") print("Before we start, we need to register an account.") User = input("Enter your name:\n") Age = input("Enter your age:\n") Year = input("Enter your year group:\n") details = [User, Age, Year] w.writerow(details) Details.close() with open("UserPass.csv", "a+") as Userpass: w = csv.writer(Userpass, delimiter=",") NewUser = (User[:3] + Age) print("Great! Your username is set to: {}".format(NewUser)) Pass = input("Enter a password for your account:\n") userpass = [NewUser, Pass] w.writerow(userpass) Userpass.close()

Answer 3

我不了解您的代码尝试完成的所有内容，但以下内容会向Details.csv添加一行而不创建任何新标题：

import csv
import os

csv_fileheader = "Name", "Age", "Year Group"
csv_filename = "Details.csv"

print("Welcome User, to my Topics Quiz!\n"
      "---------------------------------------\n"
      "You can choose from 3 different topics:\n"
      " • History\n • Music\n • Computer Science\n"
      "---------------------------------------")
print("Before we start, we need to register an account.")
user = input("Enter your name:\n")
age = input("Enter your age:\n")
year = input("Enter your year group:\n")

if not os.path.isfile(csv_filename):  # Create file if it doesn't exist.
    with open(csv_filename, "w", newline='') as csv_file:
        csv.writer(csv_file).writerow(csv_fileheader)  # Put header row in it.

with open(csv_filename, "a+", newline='') as details2:
    writer = csv.writer(details2, delimiter=",")
    writer.writerow((user, age, year))

您应该考虑遵循PEP 8 - Style Guide for Python Code建议，因为这样可以让您和其他人更轻松地阅读您的代码。

CSV重写器不断创建新标头

3 个答案: