TypeError: string argument without an encoding

问题

I want to upload compressed gzip of Json into Google Storage.

I have this code:

import datalab.storage as storage
import gzip
path = prefix + '/orders_newline.json.gz'
storage.Bucket('orders').item(path).write_to(gzip.compress(bytes(create_jsonlines(source)),encoding='utf8'), 'application/json')

The create_jsonlines(source) is a function that returns Json Newline Delimited.

Running this code gives:

TypeError: string argument without an encoding

The Python docs says the format is: bytes([source[, encoding[, errors]]]) I'm not sure I understand it as there is no example of how to use it.

I tried also

bytes([(create_jsonlines(source))[,encoding='utf8']])

This gives :

SyntaxError: invalid syntax

I'm running Python 3.5

回答1:

You are not using the bytes function correctly. Check this:

>>> a = "hi"
>>> bytes(a, encoding='utf8')
b'hi'

You can try:

bytes((create_jsonlines(source)), encoding='utf8')

encoding is the argument of the bytes function, and you are using it outside of that function.

回答2:

You are probably only one step away from the answer.

See bytesarray() and bytes for the function usage (you may need to change python version of the document).

And it says:

The optional source parameter can be used to initialize the array in a few different ways:

If it is a string, you must also give the encoding (and optionally, errors) parameters; bytearray() then converts the string to bytes using str.encode().

If it is an integer, the array will have that size and will be initialized with null bytes.

If it is an object conforming to the buffer interface, a read-only buffer of the object will be used to initialize the bytes array.

If it is an iterable, it must be an iterable of integers in the range 0 <= x < 256, which are used as the initial contents of the array.

Notice that the square bracket indicates that those parameters can be omitted, it is not an array type of python language.

So you should use bytes(create_jsonlines(source), encoding='utf8').

回答3:

When you read any python function docs as

bytes([source[, encoding[, errors]]])

square brackets represent that those parameters are optional. multiple square brackets inside another mean they are next level of option params. For example