Python try/except not working
Trying to get the try/except
statement working but having problems. This code will take a txt file and copy the file that is in location row 0 to location of row 1. It works however if i change one of the paths to invalid one it generates an error ftplib.error_perm
however the except command is not picking up and everything stops. What am i doing wrong? Python 2.4
import csv
import operator
import sys
import os
import shutil
import logging
import ftplib
import tldftp
def docopy(filename):
ftp = tldftp.dev()
inf = csv.reader(open(filename,'r'))
sortedlist = sorted(inf, key=operator.itemgetter(2), reverse=True)
for row in sortedlist:
src = row[0]
dst = row[1]
tldftp.textXfer(ftp, "RETR " + src, dst)
def hmm(haha):
result = docopy(haha);
try:
it = iter(result)
except ftplib.error_perm:
print "Error Getting File"
if __name__ == "__main__":
c = sys.argv[1]
if (c == ''):
raise Exception, "missing first parameter - row"
hmm(c)
The except
clause will only catch exceptions that are raise
d inside of their corresponding try
block. Try putting the docopy
function call inside of the try
block as well:
def hmm(haha):
try:
result = docopy(haha)
it = iter(result)
except ftplib.error_perm:
print "Error Getting File"
The point in the code which raises the error must be inside the try
block. In this case, it's likely that the error is raised inside the docopy
function, but that isn't enclosed in a try
block.
Note that docopy
returns None
. As such, you will raise an exception when you try to make an iter
out of None
-- but it won't be a ftplib.error_perm
exception, it'll be a TypeError
If you are not sure of what exception will occur, the use the code below, because if especifies for example: except StandardError: and is not that error the exception will not be process.
try:
# some code
except Exception: # Or only except:
print "Error" # Python 3: print("Error")