Rustam Umarov Rustam Umarov - 1 month ago 8
Python Question

Cannot access nested dictionary in python

Introduction:

I am trying to access nested dictionary element in python, which looks like this:

{'CA':{'1':'3','2':'3','3':'3'},'IL': {'1':'31','2':'45','3':'23'},...}


Firstly I read from Excel file, where I get names of states and then assign a dictionary to each state. This is how I do it:

xls_file = pd.ExcelFile('D:/CollegeScorecardDataDictionary-08-18-2016.xlsx')
dfEx = xls_file.parse('Church') # Parse Church sheet
for (i, item) in enumerate(stateName):
if stateChurchDict.get(item)<>None:
continue
else:
stateChurchDict[item] = dict


Once loop is iterated, I have something like this:

{'CA':<type dict>,'IL': <type dict>,'AL': <type dict>...}


In each state there are lots of churches which can be categorized in either
'1', '2' or '3'

This is where I got the numbers in the nested dictionaries.

My problem is I want to refer to a nested dictionary of certain state like

stateChurchDict['AL']['3']


and get the number of churches under category '3' in a certain state. However, firstly I have to check if it empty or not, if it is empty the value has to be added. Thus, I came up with this:

for (i, item) in enumerate(stateName):
if stateChurchDict[stateName[i-1]]['3'] <> None:
stateChurchDict.update({stateChurchDict[stateName[i-1]]['3']: stateChurchDict[stateName[i-1]]['3'] + 1})
else:
stateChurchDict[stateName[i-1]]['3'] = 1


BUT, this
stateChurchDict[stateName[i-1]]['3']
cannot access the nested dictionary, however
stateName[i-1] == 'AL'
and it calls the element like
stateChurchDict['AL']['3']
and still nothing.

Any help is greatly appreciated.

I am posting the whole stuff for a better explanation:

import pandas as pd
from collections import defaultdict, Counter
def IsNumeric(x):
try:
float(x)
return x
except:
return 0
xls_file = pd.ExcelFile('D:/CollegeScorecardDataDictionary-08-18-2016.xlsx')
dfEx = xls_file.parse('Church') # Parse data_dictionary sheet
dfCsv = pd.read_csv('D:/MERGED2014_15_PP.csv', low_memory=False)
churchCode = dfEx.Code # Label column
churchName = dfEx.ChurchName # Value column
churchCategory = dfEx.Category # Church category
relafil = dfCsv.RELAFFIL # Religious Id in CSV
stateName = dfCsv.STABBR # Name of state
churchList = {} # Create dictionary to store churches
stateChurchDict = defaultdict(Counter) # Create dictionary to store churches by state
stateChurchTemp = {} #Sepate dictionary for churches by state
# Put values into dictionary
for (i, v) in enumerate(churchCode):
churchList[v] = churchCategory[i] #Assigns a category to each church in state

for (i, item) in enumerate(stateName): #Create a dictionary as a value to each state in the stateChurchList dictionary
if item <> None:
if stateChurchDict.get(item) <> None:
continue
else:
stateChurchDict[item] = {}

for (i, item) in enumerate(stateName): #Iterate through states and count the number of churches by categories. Once the state name is changed, the number needs to be transferred from stateChurchTemp to stateChurchDict
if IsNumeric(relafil[i]) <> 0:
if i >= 1 and item <> stateName[i - 1]:
if stateChurchDict[stateName[i - 1]][3] <> None:
stateChurchDict.update({stateChurchDict[stateName[i - 1]][3]: stateChurchDict[stateName[i - 1]][
3] + IsNumeric(
stateChurchTemp[3])})
else:
stateChurchDict[stateName[i - 1]][3] = IsNumeric(stateChurchTemp[3])
if stateChurchDict[stateName[i - 1]][2] <> None:
stateChurchDict.update({stateChurchDict[stateName[i - 1]][2]: stateChurchDict[stateName[i - 1]][
2] + IsNumeric(
stateChurchTemp[2])})
else:
stateChurchDict[stateName[i - 1]][2] = IsNumeric(stateChurchTemp[2])
if stateChurchDict[stateName[i - 1]][1] <> None:
stateChurchDict.update({stateChurchDict[stateName[i - 1]][1]: stateChurchDict[stateName[i - 1]][
1] + IsNumeric(
stateChurchTemp[1])})
else:
stateChurchDict[stateName[i - 1]][1] = IsNumeric(stateChurchTemp[1])
if churchList.get(relafil[i]) <> None and stateChurchTemp.get(churchList.get(relafil[i])) <> None:
stateChurchTemp.update({churchList.get(relafil[i]): stateChurchTemp.get(churchList.get(relafil[i])) + 1})
else:
stateChurchTemp[churchList.get(relafil[i])] = 1
print stateChurchDict

Answer

You are not calling the nested dictionary, you trying to update the main one. Please change this line:

stateChurchDict.update({stateChurchDict[stateName[i - 1]][2]: stateChurchDict[stateName[i - 1]][2] + IsNumeric(stateChurchTemp[2])})

with this:

stateChurchDict.get(statename[i-1]).update({3: stateChurchDict[stateName[i - 1]][3] + IsNumeric(stateChurchTemp[3])})