How to read and store values from a text file into a dictionary. [python]

Question

I'm trying to figure out how to open up a file and then store it's contents into a dictionary using the Part no. as the key and the other information as the value. So I want it to look something like this:

{Part no.: "Description,Price", 453: "Sperving_Bearing,9900", 1342: "Panametric_Fan,23400",9480: "Converter_Exchange,93859"}

I was able to store the text from the file into a list, but I'm not sure how to assign more than one value to a key. I'm trying to do this without importing any modules. I've been using the basic str methods, list methods and dict methods.

Answer 1

For a txt file like so

453     Sperving_Bearing    9900
1342    Panametric_Fan      23400
9480    Converter_Exchange  93859

You can just do

>>> newDict = {}
>>> with open('testFile.txt', 'r') as f:
        for line in f:
            splitLine = line.split()
            newDict[int(splitLine[0])] = ",".join(splitLine[1:])


>>> newDict
{9480: 'Converter_Exchange,93859', 453: 'Sperving_Bearing,9900', 1342: 'Panametric_Fan,23400'}

You can get rid of the ----... line by just checking if line.startswith('-----') .

EDIT - If you are sure that the first two lines contain the same stuff, then you can just do

>>> testDict = {"Part no.": "Description,Price"}
>>> with open('testFile.txt', 'r') as f:
        _ = next(f)
        _ = next(f)
        for line in f:
            splitLine = line.split()
            testDict[int(splitLine[0])] = ",".join(splitLine[1:])       
>>> testDict
{9480: 'Converter_Exchange,93859', 'Part no.': 'Description,Price', 453: 'Sperving_Bearing,9900', 1342: 'Panametric_Fan,23400'}

This adds the first line to the testDict in the code and skips the first two lines and then continues on as normal.

Answer 2

You can read a file into a list of lines like this:

lines = thetextfile.readlines()

You can split a single line by spaces using:

items = somestring.split()

Here's a principial example how to store a list into a dictionary:

>>>mylist = [1, 2, 3]
>>>mydict = {}
>>>mydict['hello'] = mylist
>>>mydict['world'] = [4,5,6]
>>>print(mydict)

Containers like a tuple, list and dictionary can be nested into each other as their items.

To itereate a list you have to use a for statement like this:

for item in somelist:
    # do something with the item like printing it
    print item

Answer 3

Here's my stab at it, tested on Python 2.x/3.x:

import re

def str2dict(filename="temp.txt"):
    results = {}
    with open(filename, "r") as cache:
        # read file into a list of lines
        lines = cache.readlines()
        # loop through lines
        for line in lines:
            # skip lines starting with "--".
            if not line.startswith("--"):
                # replace random amount of spaces (\s) with tab (\t),
                # strip the trailing return (\n), split into list using
                # "\t" as the split pattern
                line = re.sub("\s\s+", "\t", line).strip().split("\t")
                # use first item in list for the key, join remaining list items
                # with ", " for the value.
                results[line[0]] = ", ".join(line[1:])

    return results

print (str2dict("temp.txt"))

Answer 4

You should store the values as a list or a tuple. Something like this:

textname = input("ENter a file")
thetextfile = open(textname,'r')
print("The file has been successfully opened!")
thetextfile = thetextfile.read()
file_s = thetextfile.split()
holder = []
wordlist = {}
for c in file_s:
   wordlist[c.split()[0]] = c.split()[1:]

Answer 5

Your file should look like this:

Part no.;Description,Price
453;Sperving_Bearin,9900
1342;Panametric_Fan,23400
9480;Converter_Exchange,93859

Than you just need to add a bit of code:

d = collections.OrderedDict()
reader = csv.reader(open('your_file.txt','r'),delimiter=';')
d = {row[0]:row[1].strip() for row in reader}
for x,y in d.items():
     print x
     print y