从CSV读取时，Python错误列表索引超出范围

Question

Hey I am trying to read data from a list that is from a CSV file

def Load(): #Loads data from the csv that can be stored in functions
global userdata
global user
userdata = []
f = open('userdata.csv','r')
data = csv.reader(f)
for row in data:
    user = []
    for field in row:
        user.append(field)
    userdata.append(user)
f.close()

This is the login function which I am looping over

def Login(): #Login function
global userdata
Load()
global user
print('Please now login to your account')

x = False
while x == False:
    usernameLog = input('Please enter your username: ')

    j = len(userdata)
    for i in range(0,j):
        if usernameLog == userdata [i][0]: #Validates username
            print('Username accepted')

            time.sleep(1)

My program successfully writes to the CSV but just doesn't read from it without throwing out this error. I might just be being stupid though.

Answer 1

You have the line user = [] inside the for loop, so you are always "cleaning" user before appending the new value, so only the last value is added, and the previous one is removed.

You should take it out of the loop, the same you are doing with userdata.

(This is what it looks like, unless your csv structure is totally different and you don't need one user per one userdata)