Creating a function that opens a file and extracts data to make a dictionary

Question

I have a text file containing this data and I need to make a function wherein this .txt file is opened, each line is read and then transferred into a python dictionary. This dictionary will have the first columns as keys and then the corresponding values would be both "Northings, Eastings".

Station Northings   Eastings
1   10001.00    10001.00
2   10070.09    10004.57
3   10105.80    10001.70

So far this is the only thing I have and it has this error when the function is called AttributeError: 'builtin_function_or_method' object has no attribute 'split'. Sorry I'm quite new to this.

def parsefile(file_name):
    station = []
    norths = []
    easts = []
    dict_station = {}
    with open(file_name) as fn:
        for line in fn:
            (stat,north,east) = line.split()
            stat.append(stat)
            norths.append(north)
            easts.append(east)
            dict_station[stat] = (north,east)
            print(station, norths, easts)
        
        return dict_station

I cannot recreate your error. Your code has errors though. Check for typos like using `stat` as a string variable and then trying to append to it. — wbg, Mar 25 '21 at 01:56
@avatar-korra Do you want to have header row as a part of your dictionary? — Hetal Thaker, Mar 25 '21 at 02:04

jbflow · Accepted Answer · 2021-03-25T02:20:01.337

0

The only error is that your trying to append to stat instead of station.

But your also doing a bunch of unnecessary stuff. This runs and is more efficient.

def parsefile(file_name):
    dict_station = {}
    with open(file_name) as fn:
        for line in fn:
            stat,north,east = line.split()
            dict_station[stat] = (north,east)
    return dict_station

edited Mar 25 '21 at 02:20

answered Mar 25 '21 at 01:55

jbflow

384
1
11

Thank you! It worked now and I see why the other stuff I did wasn't needed. – rilke-nz Mar 25 '21 at 02:01
1

I'd move the return to happen at the end of the function rather than the context `with`. – wbg Mar 25 '21 at 02:02
Yeah good point - edited. – jbflow Mar 25 '21 at 02:06
can i ask why should the return be at the end of the function? – rilke-nz Mar 25 '21 at 02:16
1

Because `with` opens the file, does something with it then closes it again. It's best to let it close then return. – jbflow Mar 25 '21 at 02:18
1

Some more reading here https://stackoverflow.com/questions/3012488/what-is-the-python-with-statement-designed-for – jbflow Mar 25 '21 at 02:19
thanks for the references ! i will read up on that – rilke-nz Mar 25 '21 at 02:47

Hetal Thaker · Answer 2 · 2021-03-25T02:24:21.350

As Station, Northings and Eastings have single value, instead of creating separate list for them try using below code here i am not considering first row to be stored as dictionary:

def parsefile(file_name):
    dict_station = {}
    with open(file_name) as fn:
        next(fn)
        for line in fn:
            temp = line.split()
            dict_station[temp[0]] = (temp[1],temp[2])
    return dict_station

Creating a function that opens a file and extracts data to make a dictionary

2 Answers2