Question

使用本机Python 3.6加载CSV时出现问题，并且控制台返回TypeError: 'NoneType'object is not iterable。

CSV包含2列，分别是department_id（int）和department（string）。

由于这是类型错误，所以我希望这很简单，但是我睡眠不足，我只需要这样做即可。这是我在CSV中读取的代码。任何帮助将不胜感激，因为我认为这应该是一个简单的解决方法（也许）。

#write function to create dict of department and within each a dict of # of count of purchase and number of first orders 
def get_department_entry(departments, line):


   data = line.strip().split(',')

   if len(data) == 2:   
      # create a dictionary entry 
      # allows us to reference the product info using product id
      # we also create a "metrics" : { "request_count": "0", "number_of_first_orders" : "0" } which 
      # will hold our metric information 
      department_info = {"department_id": data[0], "departments": data[1]}

      return departments.update({data[0] : department_info})
   else: 
      return



 #*****************************************   
departments = {}
# go through the products and populate our data structure
with open("departments.csv", encoding = 'utf-8') as file_info:
#   # skip the header
   line = file_info.readline() 

   while line:
      line = file_info.readline()
      print(line)
      departments = get_department_entry(departments, line)
for entry in departments:
#   go through all the products and output the metrics   
     print(departments[entry]["department_id"], departments[entry]['department'])
 #*******************************************************

跟踪


Traceback (most recent call last):

  File "<ipython-input-24-aa6291de102a>", line 11, in <module>
    departments = get_department_entry(departments, line)

  File "<ipython-input-23-11dd6139f61e>", line 13, in get_department_entry
    return departments.update({data[0] : department_info})

AttributeError: 'NoneType' object has no attribute 'update'

Answer 1

在“ get_department_entry”方法中，您已编写

if len(data) == 3:

这将始终返回false，因为列数为2。因此，它将返回None。

这就是为什么您会收到此错误。

TypeError: 'NoneType' object is not iterable

Answer 2

您可以尝试

while line:
    line = file_info.readline()
    print(line)
    department = get_department_entry(departments, line)
    if department:
        departments.update(department)

在CSV中阅读耶稣降生时的Python 3'NoneType'

2 个答案: