Python Indentation /If statement Problem

[jseiser]

With the help of these forums, a little while ago I wrote a small code snippet in python, that telnets to our company's router, and runs 2 commands, and then shows me the output. This is fine, and program runs how I wanted. The only thing is, when a customer calls, I need to check their 'vci' number ( 1/302, 2/250) in the router, and the way my program is set up, i have to transform 1/250, into 101250 myself, then run the command. I wanted to set up the program to take a vci of 1/250 and have it check that the first part of the string is a 1, so take it, add a "01" to it, and then slap the rest of the vci back on the number, so the program will now convert for me. To do this, I needed to set up some error checking, and check which number Im given, and then format it. I tried to do this, and Im getting invalid syntax and indentation errors. I though that anything after the If statement just needs to be indented more then the if statement, I obviously have something wrong, here is the orginial code, then what i tried to add.


import sys
import telnetlib
while True:
HOST = "000.000.220.120"
password = "password"
vpc = raw_input("Enter The VPC Number: ")
tn = telnetlib.Telnet(HOST)
tn.read_until("Password: ")
tn.write(password + "\n")
tn.write("sh int atm6/0." + str(vpc) + "\n")
tn.write("sh arp | in " + str(vpc) + "\n")
tn.write("exit\n")
print tn.read_all()


Here is what i added, that doesnt work.


import sys
import telnetlib
while True:
HOST = 000.000.220.120"
password = "password"
vpc = raw_input("Enter The VPC Number: ")
If vpc[:1] = '1': # check first number
vpc = vpc[:1] + '01' + vpc[3:]
elif vpc[:1] = '2': # if its not a 1, check for a 2
vpc = vpc[:1] + '01' + vpc[3:]
elif vpc[:1] = '3': # if its neither 1 nor 2, check for 3, error if its 3
vpc = vpc[:1] + '01' + vpc[3:]
print ' Wrong Server ( 3/ VPI )'
time.sleep(5)
sys.exit(1)
elif vpc[:1] = > 3 or < 0: # if the first num is neg, or >3, error
print 'Invalid VPI'
time.sleep(5)
sys.exit(1)
tn = telnetlib.Telnet(HOST) # if its a 1 or 2, telnet & run cmd.
tn.read_until("Password: ")
tn.write(password + "\n")
tn.write("sh int atm6/0." + str(vpc) + "\n")
tn.write("sh arp | in " + str(vpc) + "\n")
tn.write("exit\n")
print tn.read_all()


Where am i going wrong? the code itself might be wrong (probably) but what is the proper 'setup' of that file? I want to get this part working, so i can make a simple gui. Thanks all

[WW]

There is an extra space in front of the third elif.

P.S. vpc[:1] is the same as vpc[0]. Also, don't you want vpc[2:] instead of vpc[3:]? E.g.


>>> vpc = '1/250'
>>> print vpc[0] + '01' + vpc[2:]
101250
>>>

[WW]

A few other problems:

When checking for equality, use ==, not =.

This line


elif vpc[:1] = > 3 or < 0:

is not going to work. First, the syntax for the comparisons is not correct, and second, vpc[:1] is a character, not an integer. I think you mean something like this:


elif vpc[0] >= '3' or vpc[0] < '0':

(but what is supposed to happen if vpc[0] is '0'?)

Actually, assuming I understand what you are trying to do, this elif clause appears to be unnecessary. At this point, you already know that vpc[0] is not '1', '2' or '3'. It looks like you could change the third elif to a simple else:.

[jseiser]

thanks for such quick answers, this forum rocks. If the first part of the vci is a 0, then the user entered the info in wrong, and the script should kick out, that was this part, or tried to be this part


elif vpc[:1] = > 3 or < 0: # if the first num is neg, or >3, error
print 'Invalid VPI'
time.sleep(5)
sys.exit(1)

Also, all my ide's tell me that syntax problem and indent problem is with the first "if" statement. Which i cant fix, if I leave it even with everything, its wrong, if i ident it more, its wrong. So they arent really allowing me any way to fix it.

[WW]

I was editing my previous response while you were responding, so you might not have seen the last sentence of my previous post. Just change that third elif to else:.

[jseiser]

Alright, I tried your changes, still says my indentation is wrong. I tried komodo, and PyScripter. I also tried to rid myself of the extra elseif. if the number is 3 I want it to error, if it isnt 3, its obviously not 1 or 2, so the number is invalid, i want it to throw an error message, and then exit.


import sys
import telnetlib
while True:
HOST = "000.000.220.120"
password = "password"
vpc = raw_input("Enter The VPC Number: ")
#this next line is where it shows error in the IDES
# does it need more indent, less indent, I cant seem to find a
# correct place to stick it.
If vpc[0] = '1':
vpc = vpc[0] + '01' + vpc[2:]
elif vpc[0] = '2': # if its not a 1, check for a 2
vpc = vpc[0] + '01' + vpc[2:]
else vpc[:0] = '3':
print ' Wrong Server ( 3/ VPI )'
time.sleep(5)
sys.exit(1)
# how can i make it error out if the number isnt 1 or 2? but isnt a 3
# either?
tn = telnetlib.Telnet(HOST)
tn.read_until("Password: ")
tn.write(password + "\n")
tn.write("sh int atm6/0." + str(vpc) + "\n")
tn.write("sh arp | in " + str(vpc) + "\n")
tn.write("exit\n")
print tn.read_all()

[Can+~]

You just published your password? Edit your first message.


If vpc[0] = '1':
vpc = vpc[0] + '01' + vpc[2:]
elif vpc[0] = '2': # if its not a 1, check for a 2
vpc = vpc[0] + '01' + vpc[2:]
else vpc[:0] = '3':
print ' Wrong Server ( 3/ VPI )'
time.sleep(5)
sys.exit(1)

could be:



if vpc[0] == '1' or vpc[0] == '2':
vpc = vpc[0] + '01' + vpc[2:]
else:
print ' Wrong Server ( 3/ VPI )'
time.sleep(5)
sys.exit(1)

*edit* Another way, more pythonish:



if vpc[0] in ('1', '2'):
vpc = vpc[0] + '01' + vpc[2:]
else:
raise "Wrong Server ( 3/ VPI )"
time.sleep(5)
sys.exit(0)


*another edit*

btw, you need to know that
a = b # Assignation, a contains the value of b now.
a == b #Comparison, return true if this are equal, false if different.

I gotta leave, got classes now :)

[jseiser]

whoa, thanks! heh, good thing i was setting this up against the test server, or that would have a potentially have become a big problem, thanks again.

[jseiser]

it works now.


import sys
import telnetlib
import time
while True:
vpc = raw_input("Enter The VPI Number: ")
if vpc[0] in ('1', '2'):
vpc = vpc[0] + '01' + vpc[2:]
HOST = "0.0.0.0"
password = "password"
tn = telnetlib.Telnet(HOST)
tn.read_until("Password: ")
tn.write(password + "\n")
tn.write("sh int atm6/0." + str(vpc) + "\n")
tn.write("sh arp | in " + str(vpc) + "\n")
tn.write("exit\n")
print tn.read_all()
#time.sleep(10)
#sys.exit(0)
else:
print "Wrong Server ( 3/ VPI ) or invalid VCI"
time.sleep(1)