python-3.x - 使用发布请求 [python] 将压缩的 numpy 数组(zlib)发送到烧瓶服务器
问题描述
我正在尝试使用 post 请求将压缩numpy
数组(用 压缩zlib
)发送到烧瓶服务器,但压缩字节对象在服务器端发生了变化。如何正确发送带有requests
post 请求的字节对象,以便我可以在服务器端解压缩?
服务器.py
from flask import Flask
from flask_restful import Resource, Api, reqparse
import json
import numpy as np
import base64
# compression
import zlib
app = Flask(__name__)
api = Api(app)
parser = reqparse.RequestParser()
parser.add_argument('imgb64')
class Predict(Resource):
def post(self):
data = parser.parse_args()
if data['imgb64'] == "":
return {
'data':'',
'message':'No file found',
'status':'error'
}
img = data['imgb64']
print('rec')
# decompress
print(type(img))
print(img)
dec = zlib.decompress(img) # this gives me error
if img:
pass
return json.dumps({
'data': 'done',
'message':'darknet processed',
'status':'success'
})
return {
'data':'',
'message':'Something when wrong',
'status':'error'
}
api.add_resource(Predict,'/predict')
if __name__ == '__main__':
app.run(debug=True, host = '0.0.0.0', port = 5000, threaded=True)
客户端.py
import numpy as np
import base64
import zlib
import requests
frame = np.random.randint(0,255,(5,5,3)) # dummy rgb image
# compress
data = zlib.compress(frame)
print('b64 encoded')
print(data)
print(len(data))
print(type(data))
r = requests.post("http://127.0.0.1:5000/predict", data={'imgb64' : data}) # sending compressed numpy array
这给了我以下错误:
TypeError: a bytes-like object is required, not 'str'
因此,我尝试将字符串转换为bytes
对象:
dec = zlib.decompress(img.encode()) # this gives me error
但是,这也给了我一个错误:
zlib.error: Error -3 while decompressing data: incorrect header check
我尝试了其他编码,它们也失败了。
我注意到的一件事是,当我在客户端打印压缩字节时,它显示:
b'x\x9c-\xcf?J\x82q\x00\x06\xe0\x0ftrVP\\C\xf4\x06\x9268\t\xcdR\x8ej.F\xa0\xe0\xd0\xa6\xa3\xe0V\x07\x10\x1cL\xc8\xd1\x03\xd4\xe4\t\x0c\x12\x84\xb6D\x0c#\xbc\x80O\xf0\x1b\x9e\xf5\xfdS\x89\xa2h\xcf\x9a\x03\xef\xc4\xf8cF\x92\r\xbf4i\x11g\xc83\x0f\x8c\xb9\xa2@\x8e\x1bn\xd91g\xc0\x91%\xd7\xdc\xf3M\x83<i:L\xa8\xf1\x19\xfa\xffw\xfd\xf0\xc5\x94:O\x9cH\x85\xcc6#\x1e\xc3\xf6\x05\xe5\xa0\xc7\x96\x04]J\\\x90\xa1\x1f~Ty\xe1\x8d\x15w|P\xe4\x95K\xb2!\xe3\x0cw)%I'
但在服务器端,接收到的字符串完全不同:
�4ig�3���@�n�1g��%���M�<i:L����w��Ŕ:O�H��6#���ǖ]J\��~Ty�w|P�K�!�w)%I
我还尝试将字节作为字符串发送,通过
r = requests.post("http://127.0.0.1:5000/predict", data={'imgb64' : str(data)})
但是,我无法解压服务器端的数据。
解决方案
看来,我不能zlib
直接发送压缩字节,所以我使用base64将数据编码为ascii
字符串。
所以,总而言之,这对我有用,numpy
数组/任何非字符串数据 -> zlib 压缩 -> base64 编码 -> 发布请求 -> 烧瓶 -> base64 解码 -> zlib 解压缩
客户端.py
import numpy as np
import base64
import zlib
import requests
frame = np.random.randint(0,255,(5,5,3)) # dummy rgb image
# compress
data = zlib.compress(frame)
data = base64.b64encode(data)
data_send = data
data2 = base64.b64decode(data)
data2 = zlib.decompress(data2)
fdata = np.frombuffer(data2, dtype=np.uint8)
print(fdata)
r = requests.post("http://127.0.0.1:5000/predict", data={'imgb64' : data_send})
服务器.py
from flask import Flask
from flask_restful import Resource, Api, reqparse
import json
import numpy as np
import base64
# compression
import zlib
import codecs
app = Flask(__name__)
api = Api(app)
parser = reqparse.RequestParser()
parser.add_argument('imgb64', help = 'type error')
class Predict(Resource):
def post(self):
data = parser.parse_args()
#print(data)
if data['imgb64'] == "":
return {
'data':'',
'message':'No file found',
'status':'error'
}
#img = open(data['imgb64'], 'r').read() # doesn't work
img = data['imgb64']
data2 = img.encode()
data2 = base64.b64decode(data2)
data2 = zlib.decompress(data2)
fdata = np.frombuffer(data2, dtype=np.uint8)
print(fdata)
if img:
return json.dumps({
'data': 'done',
'message':'darknet processed',
'status':'success'
})
return {
'data':'',
'message':'Something when wrong',
'status':'error'
}
api.add_resource(Predict,'/predict')
if __name__ == '__main__':
app.run(debug=True, host = '0.0.0.0', port = 5000, threaded=True)