未从套接字连接获取完整数据

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。 我能够获得前几个字节，但随后就中断了。

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整行数据？

我已经阅读了 python 文档，我也查看了其他示例，但我仍然弄错了。

Answer 1

您在amount_received 中查找“Fahrenheit”一词，它是数据的整数计数，而不是数据本身。接收到的数据在data 中，这是一个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），您可以在字节中搜索 b'\n'，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，它读取字节流并在找到时返回行。

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 72.0500\n'
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()