Nested Dictionary/List

[tonybrown3]

I am new to python and am trying to learn nested dictionary's but I think I am mixing some standards. So first i am not sure i am using the proper terminology so feel free to correct. I "think" what I am doing is having a key relate to a list as so...

errorlist = {

key1 : ["error1", "error2"]
key2 : ["error3", "error4"]
}

when i setup up like that i can change any aspect of what is there but i have not figured out how to add things later for example

errorlist = {

key1 : ["error1", "error2", "error5", "error6"]
key2 : ["error3", "error4"]
}

the goal is to have several devices with a list of what errors they may have active at any given time and the list is updated as more errors show. Is this a good format or would another structure be better? I have tried looking around but everything is key:value so that makes me think I might not be using dictionary correctly.

[tonybrown3]

I have narrowed it a little. If I do

errorlist["key1"].append("error5")

it works but if i do

key_val = "key1"

errorlist[key_val].append("error5")

it barfs. so my update in theory works it is my reference value that is failing.

[ndc85430]

You're going to need to show the code (a minimal, complete working example), plus the full traceback of the error. From the last post, the two lines look equivalent.

[buran]

Also, this:

errorlist = {

key1 : ["error1", "error2"]
key2 : ["error3", "error4"]
}

would raise NameError if key1 is not defined before that. Or you want key1 and key2 in quotes.

[perfringo]

Problem as described has little to do with dictionaries. Strings are immutable and don't have .append() method:

>>> s = 'abc'
>>> s.append('d')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'str' object has no attribute 'append'

Regarding dictionaries: just an idea:

>>> keys = 'first', 'second', 'third'
>>> d = dict()
>>> for i, key in enumerate(keys):
...     d.setdefault(key, []).append(i)
... 
>>> d
{'first': [0], 'second': [1], 'third': [2]}

[tonybrown3]

Thanks for the info. I had not posted what code I had because it was a mess of attempts at learning dictionary. After some coffee and RTFM I got this working. So now it is a issue of expanding it for other units and seeing if the code is clean enough.

#!/usr/bin/python3

import sys
import os
import subprocess

class ErrorFind():
def __init__(self):
self.APC_Error_List = {
"0x3408":"Internal power supply #1 fault.",
"0x340A":"Internal power supply #2 fault.",
"0x3414":"Device overload.",
"0x341A":"Phase overload.",
"0x3420":"Bank overload.",
"0x3426":"Outlet overload.",
"0x3410":"Device low load.",
"0x3412":"Device near overload.",
"0x3416":"Phase low load.",
"0x3418":"Phase near overload.",
"0x341C":"Bank low load.",
"0x341E":"Bank near overload.",
"0x3422":"Outlet low load.",
"0x3424":"Outlet near overload."
}
self.ServerTech_Error_List = []
self.Error_Results = {}
self.grep_search_holder = "Holds grep result while looping through error codes"

#Uses grep to search syslog dir /var/log/pdu/ for the error in the error list. Then the readable version is used to call a sorting method
def Search_Code(self):
for code in self.APC_Error_List:
self.grep_search_holder = str(subprocess.check_output(["grep -r " + code + " /var/log/pdu/ | sed '/rsyslog/d' | awk '{print $2}' | sort -u "], shell=True).decode('utf-8'))
Code2Text = self.APC_Error_List.get(code)
self.Sort_Code(Code2Text)

#This takes the string of IPs and removes one at a time as it is proccessed into the dictionary. The IP is changed to DNS name as it is stored.
#If the PDU already has a entry the saved info is appeneded to the new addtional info.
def Sort_Code(self, codepass):
count = self.grep_search_holder.count("\n")
for segment in range(count):
NextIP = (self.grep_search_holder.find('\n'))
ActiveIP = (self.grep_search_holder[0: NextIP])
ActiveIP = str(ActiveIP.strip())
ActiveIP2Name = str(subprocess.check_output(["nslookup " + ActiveIP + " | grep name | awk '{print $4}'"], shell=True).decode('utf-8')).strip(".\n")
self.grep_search_holder = self.grep_search_holder[NextIP+1:]
if ActiveIP2Name not in self.Error_Results:
self.Error_Results[ActiveIP2Name] = codepass
else:
CurrentData = self.Error_Results.get(ActiveIP2Name)
UpdatedData = (CurrentData + ", " + codepass)
self.Error_Results[ActiveIP2Name] = UpdatedData

def Save_Data(self):
for key in self.Error_Results:
Print_Error = open('error.txt', 'at')
Print_Error.write(key + " " + self.Error_Results.get(key))
Print_Error.write ("\n")
Print_Error.close()

# ------------------------- end of class -------------------------------------
# ------------------------- main --------------------------------------------
error_obj=ErrorFind()
error_obj.Search_Code()
error_obj.Save_Data()
[root@rsyslog ~/scripts ]#

output sample

pdu-dur3-92ag-2.datadomain.com Internal power supply #2 fault.
pdu-dur-12f-1.datadomain.com Internal power supply #2 fault.
pdu-dur-122m-2.datadomain.com Device overload., Phase overload., Device near overload., Phase near overload.
pdu-dur-22ao-1.datadomain.com Device overload., Phase overload., Bank overload., Device near overload., Phase near overload., Bank near overload.
pdu-dur-96af-1.datadomain.com Device overload., Phase overload., Bank overload., Device near overload., Phase near overload., Bank near overload.
pdu-dur-36j-1.datadomain.com Device overload., Phase overload., Bank overload., Device near overload., Phase near overload., Bank near overload.
pdu-dur-86d-1.datadomain.com Device overload., Phase overload., Bank overload., Device near overload., Phase near overload., Bank near overload.