如何去除字符串中数字旁的方括号 [ ]?
我是一名来自荷兰的工业机械化（工程）专业的学生，最近开始学习Python脚本编写，因为这个项目，所以我现在还很菜。
我正在制作一个程序，它可以从Omron PLC获取信息，然后通过树莓派发送到MySQL数据库进行存储。
我已经成功建立了Omron PLC到树莓派的连接，可以看到它发送的数据。树莓派到MySQL的连接也已经搞定。
但是，PLC发送的数据外面有一些方括号[<---on the outside--->]，而MySQL不允许使用这些方括号，那我该怎么去掉它们呢？
看起来这些数据是嵌入在一个数组里的。
如果你需要更多信息来帮助我，我很乐意提供。
谢谢，
丹尼尔 V
# Echo client program
import socket
import re
#--------------------------------------------------------------------
import MySQLdb
#--------------------------------------------------------------------
#HOST = '192.168.200.50' # The remote host
#PORT = 9600 # The same port as used by the server
#s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
#s.connect((HOST, PORT))
finsErrorsStrings = {
0x0000000:None,
0x0000001:'The header is not FINS (ASCII code)',
0x0000002:'The data length is too long.',
0x0000003:'The command is not supported.',
0x0000020:'All connections are in use.',
0x0000021:'The specified node is already connected.',
0x0000022:'Attempt to access a protected node from an unspecified IP',
0x0000023:'The client FINS node address is out of range.',
0x0000024:'The same FINS node address is being used by the client and server.',
0x0000025:'All the node addresses available for allocation have been used.',
}
def int2str4(k):
return chr((k>>24) & 0xff) + chr((k>>16) & 0xff) + chr((k>>8) & 0xff) + chr((k>>0) & 0xff)
def int2str3(k):
return chr((k>>16) & 0xff) + chr((k>>8) & 0xff) + chr((k>>0) & 0xff)
def int2str2(k):
return chr((k>>8) & 0xff) + chr((k>>0) & 0xff)
def binstr2int(s):
n = 0
for i in range(0, len(s)):
n += ord(s[i]) * ( 1<<(8*( len(s)-i-1)))
return n
def str2intlist(s):
return [ord(c) for c in s]
def intlist2str(l):
return ''.join([chr(e) for e in l])
def wordlist2str( wl):
if wl[0] != 0xff:
print '-- Neplatna'
return ''
cs = ''
for d in wl[1:]:
n1 = ((d>>8) & 0xFF)
n2 = (d & 0xFF)
if n1==0:
break
if n2==0:
cs += chr( n1)
break
cs += chr( n1) + chr( n2)
return cs
class FinsTCPframe():
def __init__(self, cmdData='', rawFinsCmd = None, cmdFlags = None, DA1=None, SA1=None, MRC=None, SRC=None, command=0x02, errorCode=0x00, serverAdr = 0, clientAdr = 0, rawTcpFrame=None ):
self.FINScommandFlags= ['ICF','RSV','GCT','DNA','DA1','DA2','SNA','SA1','SA2','SID','MRC','SRC','data']
if rawTcpFrame:
self.fromRaw = True
self.rawTcpFrame = rawTcpFrame
else:
self.fromRaw = False
if (MRC or SRC or cmdData) :
#have some command data
commandFlags = [
0x80, # ICF
0x00, # RSV 'RSV':0
0x02, #'GCT':0x02
0x00, #'DNA':0
serverAdr, #'DA1':0
0x00, #'DA2':0
0x00, #'SNA':0
0x00, #'SA1':0
clientAdr, #'SA2':0
0x00, #'SID':0
MRC, #'MRC':0
SRC, #'SRC':0
]
if cmdFlags:
for k in cmdFlags.keys() :
commandFlags[ self.FINScommandFlags.index( k)] = cmdFlags[k]
commandFrame = intlist2str(commandFlags) + cmdData
else:
#frame have TCPheader only or raw Fins Command Packet Provided
if rawFinsCmd :
commandFrame = rawFinsCmd
else:
commandFrame = ''
self.rawTcpFrame ='FINS'
self.rawTcpFrame += int2str4( 8 + len( commandFrame)) #frame length
self.rawTcpFrame += int2str4( command)
self.rawTcpFrame += int2str4( errorCode)
self.rawTcpFrame += commandFrame
def makeFrame(self):
self.finsFrame = 'FINS'
self.frameLength = 8 + len( self.finsCmdFrame)
self.finsFrame += int2str4( self.frameLength)
self.finsFrame += int2str4( self.finsCommand)
self.finsFrame += int2str4( self.finsErrorCode)
self.finsFrame += self.finsCmdFrame
return self.finsFrame
@property
def raw(self):
return self.rawTcpFrame
@property
def disassembled(self):
asm = {
'header' : binstr2int( self.rawTcpFrame[ 0: 4] ),
'length' : binstr2int( self.rawTcpFrame[ 4: 8] ),
'command' : binstr2int( self.rawTcpFrame[ 8:12] ),
'errCode' : binstr2int( self.rawTcpFrame[12:16] ),
}
if( asm['command'] == 2) :
asm[ 'ICF'] = binstr2int( self.rawTcpFrame[16])
asm[ 'RSV'] = binstr2int( self.rawTcpFrame[17])
asm[ 'GCT'] = binstr2int( self.rawTcpFrame[18])
asm[ 'DNA'] = binstr2int( self.rawTcpFrame[19])
asm[ 'DA1'] = binstr2int( self.rawTcpFrame[20])
asm[ 'DA2'] = binstr2int( self.rawTcpFrame[21])
asm[ 'SNA'] = binstr2int( self.rawTcpFrame[22])
asm[ 'SA1'] = binstr2int( self.rawTcpFrame[23])
asm[ 'SA2'] = binstr2int( self.rawTcpFrame[24])
asm[ 'SID'] = binstr2int( self.rawTcpFrame[25])
asm[ 'MRC'] = binstr2int( self.rawTcpFrame[26])
asm[ 'SRC'] = binstr2int( self.rawTcpFrame[27])
if self.fromRaw :
#decode from response
asm[ 'MRES'] = binstr2int( self.rawTcpFrame[28])
asm[ 'SRES'] = binstr2int( self.rawTcpFrame[29])
asm['response'] = self.rawTcpFrame[30:]
else :
asm['cmd'] = self.rawTcpFrame[28:]
return asm
@property
def error(self):
#return None if ok, else errorstring as string
try:
ec = binstr2int( self.rawTcpFrame[12:16])
if ec == 0:
ec = None
except:
ec = 'Error code not found'%self.finsErrorCode
return ec
@property
def command(self):
return binstr2int( self.rawTcpFrame[ 8:12])
@property
def commandResponse(self ):
return self.rawTcpFrame[30:]
@property
def finsData(self):
"""Return raw data after FINS TCP header"""
return self.rawTcpFrame[16:]
def __str__(self):
asm = self.disassembled
str = ''.join([ "{0}:{1} ".format(k, asm[k], ) for k in asm.keys()])
return str
class OmronPlcFinsTcp():
def __init__(self, host, port):
self.port = port
self.host = host
self.sock = None
self.open = False
self.clientNode = 0
self.serverNode = 0
self.sid=0x04
@property
def _nextSid(self):
self.sid = (self.sid + 1 ) & 0xff
return self.sid
def openn(self):
if self.open :
#close if already open
self.sock.close()
self.open = False
#open socket
self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.sock.connect((self.host, self.port))
self.sock.settimeout( 1)
#start establish fins communication
print 'FINS cmd: request address'
c1 = FinsTCPframe ( command = 0, rawFinsCmd = int2str4(0))
print "Sending: " + str( c1)
self._send( c1.raw)
r1raw = self._recieve()
r1 = FinsTCPframe( rawTcpFrame = r1raw )
print "Recieved: " + str( r1)
if r1.error:
print 'Error in adress assign response: %s' % r1.error
try :
print ' - this mean>%s' % finsErrorsStrings[r1.error]
except :
pass
return False
#set client and server address against response
if r1.command != 1 :
print 'Error bad response for adress assign command: ' % r1.command
return False
self.clientNode = binstr2int( r1.finsData[0:4])
self.serverNode = binstr2int( r1.finsData[4:8])
print 'FINS address client:{0},server{1}'.format(self.clientNode, self.serverNode, )
#Get PLC type as test dummmy command
return self.doFinsCommand( MRC=0x05, SRC=0x01, cmdData = '\x00')[0:20]
def doFinsCommand(self, MRC, SRC, cmdData):
#cmdData='', rawFinsCmd = None, cmdFlags = None, DA1=None, SA1=None, MRC=None, SRC=None, command=0x02, errorCode=0x00, serverAdr = 0, clientAdr = 0, rawTcpFrame=None ):
c = FinsTCPframe(MRC=MRC, SRC=SRC, cmdData = cmdData, serverAdr=self.serverNode, clientAdr=self.clientNode, cmdFlags = {'SID':self._nextSid} )
#print "Sending: " + str( c)
self._send(c.raw)
r_raw = self._recieve()
r = FinsTCPframe( rawTcpFrame = r_raw )
#print "Recieved: " + str( r)
#print " disasm>" + str(r.disassembled)
#TODO: check error and status..
return r.commandResponse
def close(self):
self.sock.close()
self.open = False
def _send(self, raw):
self.sock.send( raw)
#print ' Send:' + repr(raw)
def _recieve(self):
pr = self.sock.recv(8)
length = binstr2int( pr[4:8])
r = pr + self.sock.recv( length)
#print ' Recv:' + repr(r)
return r
class OmronPLC():
def __init__(self):
self.conType = None
self.plcType = None
self.MEMCODES = {
#'MemType':(word,bit)
'C':(0x30, 0xB0),
'W':(0x31, 0xB1),
'H':(0x32, 0xB2),
'A':(0x33, 0xB3),
'D':(0x02, 0x82),
}
def openFins(self, address, port=9600):
self.conType = 'FINS'
self.conn = OmronPlcFinsTcp( address, port)
self.plcType = self.conn.openn()
if (self.plcType) :
print 'Open successfull to ', self.plcType, 'at ', address
else :
raise Exception('Failed to open PLC')
def doRawFinsCommand(self, **kvarg):
self.conn.doFinsCommand( kvarg)
def close(self):
if self.conType == 'FINS':
self.conn.close()
def readMemC(self, mem, length ):
memSpec= re.search('(.)([0-9]*):?([0-9]*)',mem).groups()
( memCodeB, memCodeW) = self.MEMCODES[ memSpec[0]]
#construct mem specification form
if memSpec[2] :
#BIT specs
memAdr = chr( memCodeB) + int2str2( int(memSpec[1])) + chr( int(memSpec[2]))
else:
#Word Spec
memAdr = chr( memCodeW) + int2str2( int(memSpec[1])) + chr( 0)
rawres = self.conn.doFinsCommand( MRC=0x01, SRC=0x01,
cmdData = memAdr + int2str2(length*2))
if memSpec[2] :
#bit spec
res = list( rawres)
else:
res = [ ord( rawres[i]) * 256 + ord( rawres[ i+1]) for i in range(0, len(rawres)/2, 2)]
return res
def writeMemC(self, mem, wdata ):
memSpec= re.search('(.)([0-9]*):?([0-9]*)',mem).groups()
( memCodeB, memCodeW) = self.MEMCODES[ memSpec[0]]
#construct mem specification form
if memSpec[2] :
#BIT specs
raise Exception("Bit memory write : Not Implemented")
else:
#Word Spec
memAdr = chr( memCodeW) + int2str2( int(memSpec[1])) + chr( 0)
rawdata = ''
for d in wdata:
rawdata += int2str2(d)
rawres = self.conn.doFinsCommand( MRC=0x01, SRC=0x02,
cmdData = memAdr + int2str2(len(rawdata)/2) + rawdata )
return rawres
--------------------------------------------------------------
PLC数据
import time
def main( ):
plc = OmronPLC( )
plc.openFins('11.0.0.4', 9600)
print plc.readMemC('D2010', 1)
print plc.readMemC('D2010', 2)
print plc.readMemC('D2010', 3)
print plc.readMemC('D2010', 4)
print plc.readMemC('D2010', 5)
print plc.readMemC('D2010', 6)
print plc.readMemC('D2010', 7)
print plc.readMemC('D2010', 8)
print plc.readMemC('D2010', 9)
print plc.readMemC('D2010', 10)
--------------------------------------------------------------
数据转换脚本（现在是空的）
--------------------------------------------------------------
主脚本结束
lastt = ''
plc.close()
if __name__ == "__main__":
main()
-----------------------------------------------------------
上传数据到MySQL
db = MySQLdb.connect(host="localhost", user="rendisk", passwd="raspberry",
db="rendisk_flexwaste")
sql = "INSERT INTO plc_log(data) VALUES ('%s')" % (plcput)
try:
db.cursor.execute(sql)
db.commit()
except:
db.rollback()
cursor.close()
db.close ()
-----------------------------------------------------------
这是目前这个脚本打印的内容
FINS命令：请求地址
发送：头部：1179209299 长度：12 命令：0 错误代码：0
接收：头部：1179209299 长度：16 命令：1 错误代码：0
FINS地址 客户端：251，服务器4
成功打开到 CP1L-EL20DT1-D3] 在 11.0.0.4
[3]
[3, 8]
[3, 8, 0]
[3, 8, 0, 0]
[3, 8, 0, 0, 0]
[3, 8, 0, 0, 0, 0]
[3, 8, 0, 0, 0, 0, 0]
[3, 8, 0, 0, 0, 0, 0, 0]
[3, 8, 0, 0, 0, 0, 0, 0, 0]
[3, 8, 0, 0, 0, 0, 0, 0, 0, 0]
追踪（最近的调用最后）：
文件 "/home/pi/combie.py"，第354行，在
cursor.close()
名称错误：名称 'cursor' 未定义
目前只有两个问题，一个是这个光标错误，另一个是它无法将从PLC数据中收集到的日期传输到MySQL。
3 个回答
0
如果答案总是包含这些括号，并且位置不变，你可以使用：
yourString[1:-1]
这个代码会返回从第二个字符到倒数第二个字符之间的内容。
0
d=['hai','hai1','hai2']
d=str(d)
# this part is remove the '[' from the string
for ch in ['[',']',"'",","]:
if ch in d:
d=d.replace(ch," ")
print d
结果：
hai hai1 hai2
0
看起来它还是一个数组呢！
myNumber[0]
这样就可以了哦 :)