字符串參數

Question

有人能告訴我爲什麼會收到有關python 3.下列以下錯誤是回溯：

TypeError 
Traceback (most recent call last) <ipython-input-24-a81d4875414b> in <module>() 
     7  filename = [("id"), ("name"), ("email"), ("amount"),("sent")] 
     8  writer= csv.DictWriter(temp_file, fieldnames = fieldnames) 
----> 9  writer.writeheader() 
    10 
    11  for row in reader: 
C:\Users\johsc_001\AppData\Local\conda\conda\envs\ipykernel_py3\lib\csv.py in writeheader(self) 
    142  def writeheader(self): 
    143   header = dict(zip(self.fieldnames, self.fieldnames)) 
--> 144   self.writerow(header) 
    145 
    146  def _dict_to_list(self, rowdict): 
C:\Users\johsc_001\AppData\Local\conda\conda\envs\ipykernel_py3\lib\csv.py in writerow(self, rowdict) 
    153 
    154  def writerow(self, rowdict): 
--> 155   return self.writer.writerow(self._dict_to_list(rowdict)) 
    156 
    157  def writerows(self, rowdicts): 
C:\Users\johsc_001\AppData\Local\conda\conda\envs\ipykernel_py3\lib\tempfile.py in func_wrapper(*args, **kwargs) 
    481    @_functools.wraps(func) 
    482    def func_wrapper(*args, **kwargs): 
--> 483     return func(*args, **kwargs) 
    484    # Avoid closing the file as long as the wrapper is alive, 
    485    # see issue #18879. 

TypeError: a bytes-like object is required, not 'str' 

這裏的源代碼：

import csv 
import shutil 
from tempfile import NamedTemporaryFile 
filename = 'appendpyt2.csv' 
temp_file = NamedTemporaryFile(delete= False) 
with open(filename, 'rb')as csvfile, temp_file: 
    reader =csv.DictReader(csvfile) 
    filename = ["id", "name", "email", "amount", "sent"] 
    writer= csv.DictWriter(temp_file, fieldnames = ["id", "name", "email","amout", "sent"]) 
    writer.writeheader() 
    for row in reader: 
     print(row) 
     writer.writerow({ 
      "id": row["id"], 
      "name": row["name"], 
      "email":row["email"], 
      "amout":"1234.56", 
      "sent": "" 
     }) 

Answer 1

錯誤似乎來自使用Python 3，但使用Python 2要求打開csv文件。如果使用Python 3，則不應以二進制模式打開CSV文件，並且換行符參數應爲空字符串。臨時文件也默認爲二進制模式，所以我重寫了它。我還使用以下作爲輸入文件，從代碼中推導出來，因爲沒有提供樣本輸入。

appendpyt2.csv：

id,name,email 
id1,name1,email1 
id2,name2,email2 

的Python 3代碼：

import csv 
import shutil 
from tempfile import NamedTemporaryFile 
filename = 'appendpyt2.csv' 
temp_file = NamedTemporaryFile(mode='w+',newline='',delete= False) 
with open(filename,newline='') as csvfile, temp_file: 
    reader =csv.DictReader(csvfile) 
    filename = ["id", "name", "email", "amount", "sent"] 
    writer= csv.DictWriter(temp_file, fieldnames = ["id", "name", "email","amount", "sent"]) 
    writer.writeheader() 
    for row in reader: 
     print(row) 
     writer.writerow({ 
      "id": row["id"], 
      "name": row["name"], 
      "email":row["email"], 
      "amount":"1234.56", 
      "sent": "" 
     }) 

臨時文件輸出：

id,name,email,amount,sent 
id1,name1,email1,1234.56, 
id2,name2,email2,1234.56,