if row_list[4].isdigit(): ^^^^^^^^^^^^^^^^^^^ AttributeError: 'numpy.ndarray' object has no attribute 'isdigit'

这个错误是因为numpy.ndarray对象没有isdigit()方法，所以不能在其上调用该方法。isdigit()方法是字符串对象的方法，用于检查字符串是否只包含数字字符。因此，您需要将numpy.ndarray对象转换为字符串对象，然后再调用isdigit()方法。您可以使用astype()方法将numpy.ndarray对象转换为字符串对象，如下所示：

if str(row_list[4]).isdigit():

这将把row_list转换为字符串对象，然后再调用isdigit()方法来检查它是否只包含数字字符。

相关问题

with open('output_symbols_pin.csv', 'r') as f: reader = csv.reader(f) new_rows = [] for row in reader: if row[3].isdigit(): new_row = row[:3]+['']+row[3:] new_rows.append(new_row) else: new_rows.append(row) with open('ot_symbols_pin.csv.csv','w',newline='') as f: writer = csv.writer(f) writer.writerows(new_rows)这一段代码运行后为什么会出现IndexError: list index out of range这个错误

这个错误很可能是因为读取的某一行的列数小于 4（即小于等于第四列），导致在访问 row[3] 时出现了 IndexError 异常。可以在代码中加一个判断语句来避免这种情况的发生，例如：

import csv

with open('output_symbols_pin.csv', 'r') as f:
    reader = csv.reader(f)
    new_rows = []
    for row in reader:
        if len(row) > 3 and row[3].isdigit():
            new_row = row[:3]+['']+row[3:]
            new_rows.append(new_row)
        else:
            new_rows.append(row)

with open('ot_symbols_pin.csv.csv', 'w', newline='') as f:
    writer = csv.writer(f)
    writer.writerows(new_rows)

在这个示例代码中，加了一个判断条件 `len(row) > 3`，用来判断当前行的列数是否大于 3，只有大于 3 的行才能进入 if 语句进行处理。这样就能避免访问 row[3] 时出现 IndexError 异常的情况。

from opreation_product import ProductOperation from operation_customer import CustomerOperation from operation_order import OrderOperation po = ProductOperation() co = CustomerOperation() oo = OrderOperation() class IOInterface: def show_list(self,user_role, list_type, object_list): while 1: user_inputs = self.get_user_input('please enter your the list type ' 'and page number that you want to view:') list_type = user_inputs[0] if not list_type.isalpha() and not user_inputs[1].isdigit(): print('invalid input') continue elif user_role == 'customer' and list_type == 'Customer': print('you are only allowed to view Products information and Orders information') continue else: if list_type == 'Customer': object_list = co.get_customer_list(user_inputs[1])[0] row_numbers = len(object_list) total_pages = co.get_customer_list(user_inputs[1])[2] print(object_list,row_numbers,total_pages) break elif list_type == 'Product': object_list = po.get_product_list(user_inputs[1])[0] row_numbers = len(object_list) total_pages = po.get_customer_list(user_inputs[1])[2] print(object_list, row_numbers, total_pages) break elif list_type == 'Order': object_list = oo.get_order_list(user_inputs[1])[0] row_numbers = len(object_list) total_pages = oo.get_order_list(user_inputs)[2] print(object_list, row_numbers, total_pages) break else: print('invalid input, Try again') continue 为什么这个方法中的参数list_type和object_list没有用到 该怎么改？

在该方法中，list_type和object_list参数在函数签名中被定义，但在函数体中没有被使用。如果想使用这两个参数，可以在函数中将它们传递给其他方法或函数进行处理。例如，可以将object_list传递给另一个方法，该方法可以处理对象列表并将其打印出来。而list_type参数可以用来判断用户想要查看的列表类型，从而选择正确的操作对象。以下是修改后的代码示例：

from opreation_product import ProductOperation 
from operation_customer import CustomerOperation 
from operation_order import OrderOperation 

po = ProductOperation() 
co = CustomerOperation() 
oo = OrderOperation() 

class IOInterface:  
    def show_list(self, user_role, list_type, object_list):
        while 1:
            user_inputs = self.get_user_input('please enter the list type and page number that you want to view:')
            list_type = user_inputs[0]
            if not list_type.isalpha() and not user_inputs[1].isdigit():
                print('invalid input')
                continue
            elif user_role == 'customer' and list_type == 'Customer':
                print('you are only allowed to view Products information and Orders information')
                continue
            else:
                if list_type == 'Customer':
                    object_list = co.get_customer_list(user_inputs[1])[0]
                    row_numbers = len(object_list)
                    total_pages = co.get_customer_list(user_inputs[1])[2]
                    self.print_object_list(object_list, row_numbers, total_pages)
                    break
                elif list_type == 'Product':
                    object_list = po.get_product_list(user_inputs[1])[0]
                    row_numbers = len(object_list)
                    total_pages = po.get_customer_list(user_inputs[1])[2]
                    self.print_object_list(object_list, row_numbers, total_pages)
                    break
                elif list_type == 'Order':
                    object_list = oo.get_order_list(user_inputs[1])[0]
                    row_numbers = len(object_list)
                    total_pages = oo.get_order_list(user_inputs)[2]
                    self.print_object_list(object_list, row_numbers, total_pages)
                    break
                else:
                    print('invalid input, Try again')
                    continue

    def print_object_list(self, object_list, row_numbers, total_pages):
        print(object_list, row_numbers, total_pages)

在上面的代码中，我添加了一个名为print_object_list的新方法，该方法接受object_list、row_numbers和total_pages三个参数，并将它们打印出来。在show_list方法中，当我们从操作对象中获取了对象列表时，我们将这个列表和一些其他信息传递给print_object_list方法，让它负责打印出这些信息。这样，我们就成功地使用了原本未使用的list_type和object_list参数。