CODEWITHSUNDEEP
pythoncsv
1vko
1vko

Reputation: 81

using Python to search a csv file and extract needed information

I have a large PC Inventory in csv file format. I would like to write a code that will help me find needed information. Specifically, I would like to type in the name or a part of the name of a user(user names are located in the 5th column of the file) and for the code to give me the name of that computer(computer names are located in second column in the file). My code doesn't work and I don't know what is the problem. Thank you for your help, I appreciate it!

import csv  #import csv library

#open PC Inventory file
info = csv.reader(open('Creedmoor PC Inventory.csv', 'rb'), delimiter=',')

key_index = 4   # Names are in column 5 (array index is 4)
user = raw_input("Please enter employee's name:")
rows = enumerate(info)
for row in rows:
    if row == user: #name is in the PC Inventory
        print row #show the computer name

Upvotes: 1

Views: 563

Answers (3)

abarnert
abarnert

Reputation: 365807

You've got three problems here.

First, since rows = enumerate(info), each row in rows is going to be a tuple of the row number and the actual row.

Second, the actual row itself is a sequence of columns.

So, if you want to compare user to the fifth column of an (index, row) tuple, you need to do this:

if row[1][key_index] == user:

Or, more clearly:

for index, row in rows:
    if row[key_index] == user:
        print row[1]

Or, if you don't actually have any need for the row number, just don't use enumerate:

for row in info:
    if row[key_index] == user:
        print row[1]

But that just gets you to your third problem: You want to be able to search for the name or a part of the name. So, you need the in operator:

for row in info:
    if user in row[key_index]:
        print row[1]

It would be clearer to read the whole thing into a searchable data structure:

inventory = { row[key_index]: row for row in info }

Then you don't need a for loop to search for the user; you can just do this:

print inventory[user][1]

Unfortunately, however, that won't work for doing substring searches. You need a more complex data structure. A trie, or any sorted/bisectable structure, would work if you only need prefix searches; if you need arbitrary substring searches, you need something fancier, and that's probably not worth doing.

You could consider using a database for that. For example, with a SQL database (like sqlite3), you can do this:

cur = db.execute('SELECT Computer FROM Inventory WHERE Name LIKE %s', name)

Importing a CSV file and writing a database isn't too hard, and if you're going to be running a whole lot of searches against a single CSV file it might be worth it. (Also, if you're currently editing the file by opening the CSV in Excel or LibreOffice, modifying it, and re-exporting it, you can instead just attach an Excel/LO spreadsheet to the database for editing.) Otherwise, it will just make things more complicated for no reason.

Upvotes: 2

zmo
zmo

Reputation: 24812

it's hard to tell what's wrong without knowing how your file looks like, but I'm pretty sure the error is:

for row in info:
    if row[key_Index] == user: #name is in the PC Inventory
        print row #show the computer name

where you did define the column, but forget to get that column from each line you're comparing to the user, so in the end you're comparing a string with a list.

And you don't need the enumerate, per default you iterate over the rows.

Upvotes: 0

Blender
Blender

Reputation: 298246

enumerate returns an iterator of index, element pairs. You don't really need it. Also, you forgot to use key_index:

for row in info:
    if row[key_index] == user:
        print row

Upvotes: 0

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