没有从套接字连接获得完整的数据

Question

我正在尝试编写一个从服务器接收数据流的套接字客户端。我能够得到前几个字节，但随后它中断了。

代码:

import socket
import sys
readOut = 0                 # serial data
ipaddr = "192.168.1.246"    # ip address of digital thermometer socket server
#def hitsocket(ipaddr):
#with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
print ("Starting up")
connected = False
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
try:
s.connect((ipaddr , 8080))
amount_received = 0
while True:
data = s.recv(1024)
amount_received += len(data)
if not data:
break
print(amount_received, end="n")
while True:
print ("Reading: ", amount_received)
if "Fahrenheit" in amount_received:
cread = amount_received[22:-2]
newcread = float(cread)
print("readOut ", amount_received, "cread ", cread, 
"newcread ", newcread)
break
print ("Restart")
finally:
print(sys.stderr, 'closing socket')
s.close()

输出:

Starting up
19
Writing:  1
Reading:  19
<_io.TextIOWrapper name='<stderr>' mode='w' encoding='UTF-8'> closing socket
Traceback (most recent call last):
File "climatemngrDebug-v3.py", line 58, in <module>
if "Fahrenheit" in amount_received:
TypeError: argument of type 'int' is not iterable

socket的netcat输出:

kermit@whale:~/dev $ netcat 192.168.1.246 8080
mcp9809 Fahrenheit 72.0500
mcp9809 Fahrenheit 72.0500
mcp9809 Fahrenheit 72.0500
mcp9809 Fahrenheit 72.1625
mcp9809 Fahrenheit 72.0500
mcp9809 Fahrenheit 72.0500
mcp9809 Fahrenheit 72.1625
mcp9809 Fahrenheit 72.0500

如何让我的套接字输出一行完整的数据?

我读了python文档，也看了其他的例子，但是我还是弄错了。

Answer 1

查找"华氏";在amount_received中，它是数据的整数计数，而不是数据本身。接收到的数据是data，是一个Bytes字符串。recv不知道服务器发送的行，它只是抓取一些字节。但是您可以缓冲接收数据并自己查找换行符。假设数据是字节编码的(ascii, Windows代码页，utf-8 -但不是utf-16)，您可以搜索b'n'的字节，一旦您知道有一行，将其转换为字符串以进行进一步处理。在这个例子中，我编写了一个类来读取字节流并返回找到的行。

client.py

import socket
import sys
readOut = 0                 # serial data
#ipaddr = "192.168.1.246"    # ip address of digital thermometer socket server
# todo: change as needed for test server or real server
ipaddr = 'localhost'
ipport = 8080
#def hitsocket(ipaddr):
#with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
print ("Starting up")
connected = False
class LineReader:
def __init__(self, socket, encoding='ascii'):
self.s = socket
self.encoding = encoding
self.buf = b''
self.closed = False
def readline(self):
while True:
index = self.buf.find(b'n')
if index >= 0:
line = self.buf[:index+1]
self.buf = self.buf[index+1:]
return line.decode(self.encoding)
if self.closed:
line = self.buf
self.buf = b''
return line.decode(self.encoding)
data = self.s.recv(1024)
self.closed = len(data) == 0
print("raw recv:", data)
self.buf += data
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
try:
s.connect((ipaddr , ipport))
reader = LineReader(s)
while True:
line = reader.readline()
if not line:
break
print(f"Reading: {line}", end='')
if "Fahrenheit" in line:
cread = line[22:-2]
newcread = float(cread)
print("cread ", cread, 
"newcread ", newcread)
finally:
print('closing socket', file=sys.stderr)
s.close()

testserver.py

import socket
import time
test_data =  b'mcp9809 Fahrenheit 72.0500n'
s = socket.socket()
# todo: change as needed, but must match address in client script
s.bind(('localhost', 8080))
s.listen()
while True:
c, addr = s.accept()
# send in framents to test reassembler
c.send(test_data)
time.sleep(.1)
c.send(test_data * 2)
time.sleep(.1)
c.send(test_data[:9])
time.sleep(.1)
c.send(test_data[9:])
c.send(test_data * 3 + test_data[:9])
time.sleep(.1)
c.send(test_data[9:])
c.shutdown(socket.SHUT_RDWR)
c.close()