Issue when printing dictionary

Question

I want to print the following dictionary line by line where the second line should be the list itself (in Python 2x):

dict = {1: [10, 20, 30], 2: [40, 50]}
for i in dict:
    print ("i = %s" % i)
    for j in dict[i]:
        print dict[i][j]
    print ("\n")

This is by following this answer but still having this error that said out of range!!

i = 1
Traceback (most recent call last):
  File "./t.py", line 26, in <module>
    print dict[i][j]
IndexError: list index out of range

I am learning Python by myself. I apologize if this question is trivial to most of you.

If you are just starting Python learning, best to go with Python3 — OneCricketeer, Jan 18 '17 at 19:48
First loop is for iterating over keys and the inner one iterating for values which is in this case list. — Kristofer, Jan 18 '17 at 19:49
"inner one iterating for values" -- Right. And you used the value as an index. `l[i][j]` — OneCricketeer, Jan 18 '17 at 19:49
@jonrsharpe I changed the variable but used the old error message. I am sorry. I modified the post — Kristofer, Jan 18 '17 at 19:50

score 0 · Answer 1 · answered Jan 18 '17 at 19:48

0

Just change dict[i][j] to only j

Also don't use variable as dict

d = {1: [10, 20, 30], 2: [40, 50]}
for i in d:
    print ("i = %s" % i)
    for j in d[i]:
        print j
    print ("\n")

Output:

C:\Users\dinesh_pundkar\Desktop>python dsp.py
i = 1
10
20
30


i = 2
40
50



C:\Users\dinesh_pundkar\Desktop>

answered Jan 18 '17 at 19:48

Dinesh Pundkar

4,160
1
23
37

1

Oh! thank you so much... In fact, I'd like to print the entire list not the list values – Kristofer Jan 18 '17 at 19:53

score 0 · Answer 2 · answered Jan 18 '17 at 19:48

0

You used your list values as indices into the list. Instead, just print the value:

dict = {1: [10, 20, 30], 2: [40, 50]}
for i in dict:
    print ("i = %s" % i)
    for j in dict[i]:
        print j
    print ("\n")

answered Jan 18 '17 at 19:48

Prune

76,765
14
60
81

score 0 · Answer 3 · edited Jun 20 '20 at 09:12

The list is just the value returned for the key...

First, don't 'hide' reserved words (by using 'dict' as a variable name, for instance.)

Second, the list you wish to print is just the value returned for the key provided. Your sample code is iterating over the list and then using the resultant value as an index, which it is not.

The following code is the closest to your example that does what you described you wanted it to do:

d = {1: [10, 20, 30], 2: [40, 50]}  
for i in d:  
  print ("i = %s" % i)  
  print d[i]

Which yields the following in an interactive Python session:

>>> d = {1: [10, 20, 30], 2: [40, 50]}  
>>> for i in d:  
...   print ("i = %s" % i)  
...   print d[i]  
... 
i = 1
[10, 20, 30]
i = 2
[40, 50]  
>>>

A tighter implementation might look like this:

d = {1: [10, 20, 30], 2: [40, 50]}  
for k,v in d.items():  
  print ("i = %s\n%s" % (k,v))

Which, again, yields the following in an interactive Python session:

>>> d = {1: [10, 20, 30], 2: [40, 50]}  
>>> for k,v in d.items():  
...   print ("i = %s\n%s" % (k,v))  
... 
i = 1
[10, 20, 30]
i = 2
[40, 50]
>>>

Issue when printing dictionary

3 Answers3

The list is just the value returned for the key...