how to read file line by line in python

Question

I'm trying to read below text file in python, I'm struggling to get as key value in output but its not working as expected:

test.txt

productId1 ProdName1,ProdPrice1,ProdDescription1,ProdDate1
productId2 ProdName2,ProdPrice2,ProdDescription2,ProdDate2
productId3 ProdName3,ProdPrice3,ProdDescription3,ProdDate3
productId4 ProdName4,ProdPrice4,ProdDescription4,ProdDate4

myPython.py

import sys
with open('test.txt') as f
  lines = list(line.split(' ',1) for line in f)
  for k,v in lines.items();
     print("Key : {0}, Value: {1}".format(k,v))

I'm trying to parse the text file and trying to print key and value separately. Looks like I'm doing something wrong here. Need some help to fix this?

Thanks!

Answer 1

You're needlessly storing a list.

Loop, split and print

with open('test.txt') as f:
    for line in f:
        k, v = line.rstrip().split(' ',1) 
        print("Key : {0}, Value: {1}".format(k,v))

Answer 2

This should work, with a list comprehension:

with open('test.txt') as f:
    lines = [line.split(' ',1) for line in f]
    for k, v in lines:
        print("Key: {0}, Value: {1}".format(k, v))

Answer 3

You can make a dict right of the bat with a dict comp and than iterate the list to print as you wanted. What you had done was create a list, which does not have an items() method.

with open('notepad.txt') as f:
    d = {line.split(' ')[0]:line.split(' ')[1] for line in f}
    for k,v in d.items():
        print("Key : {0}, Value: {1}".format(k,v))

Answer 4

lines is a list of lists, so the good way to finish the job is:

import sys
with open('test.txt') as f:
  lines = list(line.split(' ',1) for line in f)
for k,v in lines:
   print("Key : {0}, Value: {1}".format(k,v))

Answer 5

Perhaps I am reading too much into your description but I see one key, a space and a comma limited name of other fields. If I interpret that as their being data for those items that is comma limited then I would conclude you want a dictionary of dictionaries. That would lead to code like:

data_keys = 'ProdName', 'ProdPrice', 'ProdDescription', 'ProdDate'
with open('test.txt') as f:
  for line in f:
    id, values = l.strip().split()  # automatically on white space
    keyed_values = zip(data_keys, values.split(','))
    print(dict([('key', id)] + keyed_values))

Answer 6

You can use the f.readlines() function that returns a list of lines in the file f. I changed the code to include f.lines in line 3.

import sys
with open('test.txt') as f:
  lines = list(line.split(' ',1) for line in f.readlines())
  for k,v in lines.items();
     print("Key : {0}, Value: {1}".format(k,v))