NameError: name 'idx' is not defined

[wardancer84]

hi,

im stuck at the mentioned error. guess its easily fixable, but i cant get my head around it.

#!/usr/bin/env python

'''
populates ansible inventory db from
aix registry db
'''

# -*- coding: utf-8 -*-

import os
import sys
import pymysql as db
try:
    import json
    from json import JSONDecodeError
except ImportError:
    import simplejson as json
    from simplejson import JSONDecodeError

connections = {
    'conn1': db.connect('remotehost', 'aix_regread', '***', 'aix_registry', charset='utf8'),
    'conn2': db.connect('localhost', 'ansible', '***', 'ansible_inv', charset='utf8')
}

c1 = connections['conn1'].cursor()
c2 = connections['conn2'].cursor()

try:
    sql = """SELECT DISTINCT NODE,IP FROM ansible_hosts_view;"""
    c1.execute(sql)
    sql = """SELECT DISTINCT NODE,IP FROM ansible_hosts_view;"""
    c2.execute(sql)
    diff_to_del = (list(set(c2.fetchall()) - set(c1.fetchall())))
    for idx,row in enumerate(diff_to_del, start=1):
        host, hostname = row
        sql = """DELETE FROM host WHERE  host='{}';""".format(host)
        c2.execute(sql % (host))
    print("delete:affected rows = {}".format(idx))
    for idx,row in enumerate(c1, start=1):
        host, hostname = row
        var_data = {'inventory_lparname': host}
        var_json = json.dumps(var_data)
        ena = "1"
        sql = """INSERT INTO host(host, hostname, variables, enabled) VALUES ('%s', '%s', '%s', '%s') ON DUPLICATE KEY UPDATE
        host='{}', hostname='{}',variables='{}',enabled='{}';""".format(host, hostname, var_json, ena)
        c2.execute(sql % (host, hostname, var_json, ena))
    print("insert:affected rows = {}".format(idx))
except db.Error,e:
    print e[0], e[1]
    connections['conn2'].rollback()
    c1.close()
    c2.close()
    [conn.close() for key, conn in connections.items()]

connections['conn2'].commit()
c1.close()
c2.close()
[conn.close() for key, conn in connections.items()]

error:

Traceback (most recent call last):
File "./reg2inv.py", line 38, in <module>
print("delete:affected rows = {}".format(idx))
NameError: name 'idx' is not defined

any hints?

[Mekire]

It seems in both cases (line 38 and 47), the print lines should be indented so that they are inside their respective for loops.

[volcano63]

#!/usr/bin/env python
....
    for idx,row in enumerate(diff_to_del, start=1):
        host, hostname = row
        sql = """DELETE FROM host WHERE  host='{}';""".format(host)
        c2.execute(sql % (host))
    print("delete:affected rows = {}".format(idx))

error:

Traceback (most recent call last):
File "./reg2inv.py", line 38, in <module>
print("delete:affected rows = {}".format(idx))
NameError: name 'idx' is not defined

any hints?

Looks like diff_to_del is an empty sequence, and you loop is not entered, leaving idx undefined. Pre-set it to 0

[wardancer84]

#!/usr/bin/env python
....
    for idx,row in enumerate(diff_to_del, start=1):
        host, hostname = row
        sql = """DELETE FROM host WHERE  host='{}';""".format(host)
        c2.execute(sql % (host))
    print("delete:affected rows = {}".format(idx))

error:

Traceback (most recent call last):
File "./reg2inv.py", line 38, in <module>
print("delete:affected rows = {}".format(idx))
NameError: name 'idx' is not defined

any hints?

Looks like diff_to_del is an empty sequence, and you loop is not entered, leaving idx undefined. Pre-set it to 0

this solved my issue, thank you very much!

root@lpgaixmgmtlx01:/etc/ansible/aix/dyninv>./reg2inv.py
delete:affected rows = 0
insert:affected rows = 370

[volcano63]

Glad to be of help

I was looking back at your code - couple of pointers about this one

[conn.close() for key, conn in connections.items()]

• You can iterate over connections.values()
  
• If you iterate over a list of lists/tuples and you want to skip some values - you may leave them unnamed, using multiples of undescore(1 for first, 2 for second, etc.), like for _, conn
  
• Using a list comprehension instead of a cycle to call functions/methods is unhealthy - you create a parasitic list in memory, and in a big data environment, you may actually cause a harmful resource consumption - you are building as a side effect a list which is thrown away (IMO, it is also un-Pythonic - since you abuse the mechanism)
  

  for conn in connections.items():
      connn.close()

  probably looks less sexy - but this is the proper way