使用模块csv在Python中读取csv文件

Question

我正在尝试使用模块csv在Python中读取csv文件。 为此，我使用一个reader变量：

 with open('oneOrganization.csv', 'r', newline='') as csvfile2:
    reader2 = csv.DictReader(csvfile2, delimiter=',')

    for row in reader2:
        if row["role"] == []:
            row_dict['Role'] = "User"
        else:
            row_dict['Role'] = row["role"]

但是，运行程序时，我意识到尽管cvs文件存在，但它确实被称为oneOrganization.csv。 可能是什么原因？

我从Python开始，通常这种方法有效。

Answer 1

if row['Role']==[] ，则阻止代码访问if循环的问题是因为您试图以错误的方式查找空元素。
试试这个：

方法1：

with open('oneOrganization.csv','r') as file:
    reader = csv.DictReader(file,delimiter=',')
    my_list = list(reader)
    for row in reader:
        if row['test1'] in (None,''): # to check if cell is empty
            row_dict['Role'] = "User"
        else:
            row_dict['Role'] = row["role"]

方法2：由@ Jean-FrançoisFabre提供

with open('oneOrganization.csv','r') as file:
    reader = csv.DictReader(file,delimiter=',')
    for row in reader:
        if not row['test1']:
            row_dict['Role'] = "User"
        else:
            row_dict['Role'] = row["role"]

方法3：“优雅的一个班轮” - 来自@ Jean-FrançoisFabre

with open('oneOrganization.csv','r') as file:
    reader = csv.DictReader(file,delimiter=',')
    for row in reader:
        row_dict['Role'] = row["role"] or "User"

我尝试了一个csv示例，可以这样表示：（np.array form）

[['test1' 'test2' 'test3']
 [   1       2       3   ]
 [   11      22      33  ]
 [           222     333]]

并使用此代码：

import csv

with open('test_csv.csv','r') as file:
    reader = csv.DictReader(file,delimiter=',')
    for row in reader:
        if row['test1'] in (None,''):
            print('no')
        else:
            print(row['test1'])

或方法2：

import csv

with open('test_csv.csv','r') as file:
    reader = csv.DictReader(file,delimiter=',')
    for row in reader:
        if not row['test1']:
            print('no')
        else:
            print(row['test1'])

或方法3

import csv

with open('test_csv.csv','r') as file:
    reader = csv.DictReader(file,delimiter=',')
    for row in reader:
        print(row['test1'] or 'no')

输出：

1
11
no

您可以参考此主题以获取有关如何检查csv文件中“单元格”是否为空的更多信息。