如何在python中逐行读取文件

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))