CODEWITHSUNDEEP
pythondictionary
Rilcon42
Rilcon42

Reputation: 9763

TypeError in dictionary

I am trying to pull specific values from a dictionary but my program keeps throwing a TypeError on some values from the dictionary. Can someone tell me why?

python program

import csv,os,re,sys

input_dict = csv.DictReader(open("./MCPlayerData/AllPlayerData2.csv"))     
def list_scale_values(regexmatch,stopOnNA,person):
    data=[]
    for key in person:
        if re.match(regexmatch, key):
            try:
                data.append(int(person[key]))
            except (ValueError):
                data.append('NA') 
                if(stopOnNA):
                    data=['NA'] #if any NA return NA    
                    break
    return data

try:
    for person in input_dict:
        print(list_scale_values(r'npi[0-9]+',True,person))  
except (TypeError):
    type, value, traceback = sys.exc_info()
    print(type)
    print(value)
    print(traceback)
    print '\n---\n',person,'\n---'
    sys.exit()

print('DONE')

error output

    Traceback (most recent call last):
  File "correlations.py", line 22, in <module>
    print(list_scale_values(r'npi[0-9]+',True,person))  
  File "correlations.py", line 9, in list_scale_values
    if re.match(regexmatch, key):
  File "/usr/lib/python2.7/re.py", line 137, in match
    return _compile(pattern, flags).match(string)
TypeError: expected string or buffer

Upvotes: 1

Views: 141

Answers (1)

cmidi
cmidi

Reputation: 2020

To avoid this problem check if the key is a valid string or buffer before a regular expression is made.

so instead of if re.match(regexmatch, key):

write the following code

if key != None and re.match(regexmatch, key):

To answer the question why it would happen for some person in the csv dictionary?

If the csv file does not take into consideration for all the columns in a row for each row this situation is totally possible for only certain rows, in this case people

To give an example :

consider the following CSV file

name,type,address,value
zoo,1,111,2
foo,2,222,,
bar,3,333,5

This would get the following results for the persons in csv.DictReader(open("filename.csv"))

 {'type': '1', 'name': 'abc', 'value': '2', 'address': '111'}
 {None: [''], 'type': '2', 'name': 'foo', 'value': '', 'address': '222'}
 {'type': '3', 'name': 'bar', 'value': '5', 'address': '333'}

So in this case it would work for people[0] and people[2] but fail at people[1]

Upvotes: 1

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