Python从文件中检索带有列表的字典

Question

Hello i have a dictionary file named output.csv created by a dictionary with key:List and has the following form

A,['TEST1']

B,['TEST2']

C,"['TEST1', 'TEST3']"

D,['TEST2']

E,"['TEST1', 'TEST2']"

Now i try to access it from a different python script by using the following

reader = csv.reader(open('output.csv', 'r'))
d = {}
for row in reader:
   k, v = row
   d[k] = v

Although i get this error

line 9, in <module>
    k, v = row
ValueError: need more than 0 values to unpack

What could be the problem?

Answer 1

If you want to create the dictionary back you can do:

import csv

reader = csv.reader(open('output.csv'))
d = {}
for row in reader:
  if row:
    k = row[0]
    v = row[1]
    d[k] = v
print d

Output:

{'A': "['TEST1']", 'B': "['TEST1' 'TEST3']", 'C': "['TEST2']",
 'D': "['TEST1' 'TEST2']", 'E': "['TEST2']"}

EDIT (a little explaining): This works because the delimiter value for csv.reader() defaults to , so it returns a list with two elements in your case. You can of course set it to something else if you want, I just assumed you want to split it by commas. To set it to something else you can do:

csv.reader(open('output.csv'), delimiter=']')

Answer 2

You have empty lines and possibly some lines with spaces, which get csv-unpacked as no values or one value, respectively. Add a line to ignore those:

for row in reader:
    if len(row)!=2: continue
    k, v = row