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Finding scores from a list

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  Finding scores from a list Cai Gengyang <gengyangcai@gmail.com> - 2015-11-24 05:25 -0800
    Re: Finding scores from a list Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-11-24 13:44 +0000
    Re: Finding scores from a list Peter Otten <__peter__@web.de> - 2015-11-24 14:50 +0100
    Re: Finding scores from a list BartC <bc@freeuk.com> - 2015-11-24 14:12 +0000
    Re: Finding scores from a list John Gordon <gordon@panix.com> - 2015-11-24 17:47 +0000

#99326 — Finding scores from a list

results = [
{"id": 1, "name": "ensheng", "score": 10},
{"id": 2, "name": "gengyang", "score": 12},
{"id": 3, "name": "jordan", "score": 5},
]

I want to find gengyang's score. This is what I tried :

>>> print((results["gengyang"])["score"])

but I got an error message instead :

Traceback (most recent call last):
  File "<pyshell#62>", line 1, in <module>
    print((results["gengyang"])["score"])
TypeError: list indices must be integers, not str

Any ideas how to solve this? Thank you ..

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#99330

On 24/11/2015 13:25, Cai Gengyang wrote:
>
> results = [
> {"id": 1, "name": "ensheng", "score": 10},
> {"id": 2, "name": "gengyang", "score": 12},
> {"id": 3, "name": "jordan", "score": 5},
> ]
>
> I want to find gengyang's score. This is what I tried :
>
>>>> print((results["gengyang"])["score"])
>
> but I got an error message instead :
>
> Traceback (most recent call last):
>    File "<pyshell#62>", line 1, in <module>
>      print((results["gengyang"])["score"])
> TypeError: list indices must be integers, not str
>
> Any ideas how to solve this? Thank you ..
>

Please read and digest the TypeError.  There is a very strong hint in 
there, follow it.  Compare the type of your data structure `results` 
with the one you've used earlier today.  Spot the difference?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence

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#99332

Cai Gengyang wrote:

> 
> results = [
> {"id": 1, "name": "ensheng", "score": 10},
> {"id": 2, "name": "gengyang", "score": 12},
> {"id": 3, "name": "jordan", "score": 5},
> ]
> 
> I want to find gengyang's score. This is what I tried :
> 
>>>> print((results["gengyang"])["score"])
> 
> but I got an error message instead :
> 
> Traceback (most recent call last):
>   File "<pyshell#62>", line 1, in <module>
>     print((results["gengyang"])["score"])
> TypeError: list indices must be integers, not str
> 
> Any ideas how to solve this? Thank you ..

As the outer container is a list you have to provide an index:

results[1]["score"]

You can also search for a matching item:

for result in results:
   if result["name"] == "gengyang":
       print(result["score"])

but when the list grows performance will suffer.

General note: you will have a better experience learning Python when you 
read some introductory text first, to get the big picture.

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#99337

On 24/11/2015 13:25, Cai Gengyang wrote:
>
> results = [
> {"id": 1, "name": "ensheng", "score": 10},
> {"id": 2, "name": "gengyang", "score": 12},
> {"id": 3, "name": "jordan", "score": 5},
> ]
>
> I want to find gengyang's score. This is what I tried :
>
>>>> print((results["gengyang"])["score"])
>
> but I got an error message instead :
>
> Traceback (most recent call last):
>    File "<pyshell#62>", line 1, in <module>
>      print((results["gengyang"])["score"])
> TypeError: list indices must be integers, not str
>
> Any ideas how to solve this? Thank you ..

Your new results type is a list of dicts.

Lists are indexed by a number. That will be results[1] for the dict 
relevant to "gengyang" (not even the 2 of the "id", because lists start 
counting at 0).

To find the entry for particular name, you have to search for it (for a 
list entry where the dict key "name" gives you the value you expect, ie. 
"gengyang" in this example).

So a dict of dicts was a better idea.

-- 
Bartc

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#99375

In <277843f7-c898-4378-85ea-841b09a289e3@googlegroups.com> Cai Gengyang <gengyangcai@gmail.com> writes:


> results = [
> {"id": 1, "name": "ensheng", "score": 10},
> {"id": 2, "name": "gengyang", "score": 12},
> {"id": 3, "name": "jordan", "score": 5},
> ]

Okay, this is a list.

> I want to find gengyang's score. This is what I tried :

> >>> print((results["gengyang"])["score"])

> but I got an error message instead :

> Traceback (most recent call last):
>   File "<pyshell#62>", line 1, in <module>
>     print((results["gengyang"])["score"])
> TypeError: list indices must be integers, not str

Lists are indexed by number, not by name.

You want something like this:

    for result in results:
        if result["name"] == "gengyang":
            print result["score"]
            break

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon@panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"

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