英文:
Flask TypeError: Expected bytes
问题
我正在尝试从表格中获取数据并响应结果。我遇到了这个问题，因为数据来自数据库。以下是代码：
cursor = connection.cursor()cursor.execute("select * from table")result = cursor.fetchall()for row in result:data = rowconnection.close()return Response(data,mimetype="text/csv",headers={"Content-disposition": "attachment; filename=data.csv"},)
在尝试获取数据时，我遇到了这个错误：
TypeError: 期望的是字节
我该如何解决这个问题？
英文:
I'm trying to get data from a table and response the result. I am facing this issue since the data is from a database. Below is the code:
cursor = connection.cursor()cursor.execute("""select * from table""")result = cursor.fetchall()for row in result:data = rowconnection.close()return Response(data,mimetype="text/csv",headers={"Content-disposition": "attachment; filename=data.csv"},)
While trying to get it, I am getting this error:
TypeError: Expected bytes
How can I resolve this?
答案1
得分: 1
以下是翻译好的代码部分，不包括翻译请求的内容：
import csvfrom io import StringIO# ...# 实例化一个StringIO来在内存中缓冲CSVsio = StringIO()# 实例化一个CSV写入器来写入StringIOcw = csv.writer(sio)# 执行查询cursor.execute("""select * from table""")# 根据您的数据库，您可以在循环之前使用 `cw.writerow`# 来将列名作为第一行写入CSV。# 循环遍历查询返回的行，将每个单元格转换为字符串后写入CSV写入器。# 您可能需要调整 `str()` 调用以特定方式格式化日期等内容。for row in cursor:cw.writerow([str(cell) for cell in row])# 获取StringIO的内容并编码为UTF-8字节csv_bytes = sio.getvalue().encode("utf-8")return Response(csv_bytes,mimetype="text/csv",headers={"Content-disposition": "attachment; filename=data.csv"},)
英文:
You're probably looking for something like this. I elided the connection-related bits, because they're specific to your database connection.
import csvfrom io import StringIO# ...# Instantiate a StringIO to buffer the CSV in memory tosio = StringIO()# Instantiate a CSV writer to write to the StringIOcw = csv.writer(sio)# Execute the querycursor.execute("""select * from table""")# Depending on your database, you could use `cw.writerow`# before the loop to write the column names as the first line here.# Loop over the rows returned by the query, casting each cell to a string# before writing to the CSV writer. You may need to adjust the `str()`# invocation to format e.g. dates in a specific way.for row in cursor:cw.writerow([str(cell) for cell in row])# Get the StringIO's contents and encode to UTF-8 bytescsv_bytes = sio.getvalue().encode("utf-8")return Response(csv_bytes,mimetype="text/csv",headers={"Content-disposition": "attachment; filename=data.csv"},)
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