Question

我一直试图从Cloud Functions中的字符串创建一个csv文件。它将文件临时存储在/ tmp文件夹中。然后文件进入存储桶。

以下是我的代码-

def upload_blob(bucket_name, source_file_name, destination_blob_name):

    storage_client = storage.Client()
    bucket = storage_client.get_bucket(bucket_name)
    blob = bucket.blob(destination_blob_name)
    blob.upload_from_file(source_file_name)

message = "Data for CSV file"
csv = open('test.csv', "w")    #ERROR HERE
csv.write(message)
with open('/tmp/test.csv', 'r') as file_obj:
    upload_blob('test-bucket', file_obj, 'test.csv')

我收到以下错误-

File "/user_code/main.py", line 30, in hello_main csv = open('test.csv', 
"w") OSError: [Errno 30] Read-only file system: 'test.csv'

如何使该文件可写？

Answer 1

尝试更换：

csv = open('test.csv', "w")

具有：

csv = open('/tmp/test.csv', "w")

因为您仅在/ tmp中具有写权限

Answer 2

正如@saccodd所说，问题是您仅在/tmp directory中具有写权限。因此，替换：

csv = open('test.csv', "w")

具有：

csv = open('/tmp/test.csv', "w")

将解决该错误，但建议先关闭文件再处理。引用Python official documentation：

在处理文件时，最好使用with关键字对象。好处是文件在其被正确关闭后套件完成，即使在某个时候引发异常。使用还比编写等效的try-finally块
短得多

所以最好替换

csv = open('test.csv', "w") #ERROR HERE 
csv.write(message)

具有：

with open('/tmp/test.csv', "w") as csv: 
    csv.write(message)

使用Cloud Functions在Cloud Storage中创建CSV文件

2 个答案: