Python：如何从 CSV 文件中读取键值对？

Question

I have a csv file having 3 columns and I want to read 1st and 3rd column as key value pair. I am doing it like below but it's not working.

with open(dirName + fileName) as f:
       for line in f:
            (key, value) = line.split(',')

Answer 1

I'm thinking you want something like:

with open(dirName + fileName) as f:
       for line in f:
            fields = line.split(',')
            assert len(fields) == 3
            (key, _, value) = fields

But maybe glance at the csv module.

Answer 2

Any time you're working with csv files use the csv module .
As @Buckeye14Guy says: you should also use pathlib for path manipulations.
And, for fast lookup, you can store key-value pairs in a dictionary, d .

import csv, pathlib

d = {}
your_path = pathlib.PurePath(dirName).joinpath(filename)
with open(your_path,'r') as f:  
    reader = csv.reader(f) 
    for line in reader: 
        d[line[0]] = line[2] # dict entry with key = 1st col and value = 3rd col

Answer 3

Try this

with open(file,'r+') as text:
 for line in text.readlines():
     (key, value) = line.split(',')